Charlie Sheen appeared on the Today show Tuesday morning where he confirmed reports that he is HIV positive.
"I am in fact HIV positive," Sheen said, disclosing that he was diagnosed roughly four years ago. "I have to put a stop to this onslaught, this barrage of attacks of sub-truths and very, very harmful stories that are about threatening the health of so many others which couldn't be farther from the truth."
The former Two and a Half Men star sat down for a live interview with Today show anchor Matt Lauer, revealing that he's paid people to keep his diagnosis quiet. "I think I released myself from this prison today," he said.
MORE: Charlie Sheen Pens Open Letter About Being HIV Positive -- 'My Partying Days Are Behind Me'
Sheen said that he realized something was wrong when he started getting "a series of cluster headaches," and "sweating the bed." He said he was hospitalized two to three nights in a row.
"I thought I had a brain tumor. I thought it was over," Sheen told Lauer. "After a battery of tests, they walked in the room and said, 'Boom, here is what's going on.' It's a hard three letters to absorb. You know? It's a turning point in one's life."
PHOTOS: Celebs Living With HIV
The actor said he's not entirely sure how he contracted the disease.
Lauer read aloud a letter Sheen gave him prior to their interview. "In and around this perplexity of difficult time, I dazedly chose or hired the companionship of unsavory types," he read. "Regardless of their saltless reputations, I always led with condoms and honesty when it came to my condition, say my truth became their treason as a deluge of blackmail and circus of deceit."
When asked if he ever "knowingly or even perhaps unknowingly transmitted the HIV virus to someone else while you’ve had this," Sheen insisted that it was "impossible."
MORE: Charlie Sheen's Doctor Says Actor Has an Undetectable Level of the Virus in His Blood
The TV star did admit that he's had unprotected sex since news of his diagnosis. "The two people who I did that with were under the care of my doctor and they were completely warned ahead of time," he disclosed.
Sheen claimed that he's been shaken down for money in exchange for keeping his secret. Lauer inquired, "Is it true that on at least one occasion you had a prostitute come over to your house who, after a sexual encounter, with a cell phone, took an image of your anti-retro virus medication and then threatened to sell that image to the tabloids?"
MORE: Martin Sheen's Outspoken History of HIV and AIDS Activism
"Yes, that is after I told her thank you for your time and we are not gonna see each other anymore," Sheen explained. "After she spent the day at the health food store buying me all the medications to help me."
When Lauer asked why he allowed these people in his life, Sheen admitted that he was battling depression. "I was so depressed by the position I was in," he said. "I was doing a lot of drugs and I was making really bad decisions. That part I know 100 percent."
The actor hopes that by coming forward about his HIV status that he will help others do the same. "I have a responsibility now to better myself and to help a lot of other people," he told Lauer. "And hopefully with what we're doing today, others may come forward and say, 'Thanks Charlie. Thanks for kicking the door open.'"
Rumors of Sheen's HIV status became public following the Sony hack in 2014, when an email from Sony Pictures Television Chairman Steve Mosko seemingly made reference to the 50-year-old actor being HIV positive.
WATCH: Charlie Sheen's Ex Brooke Mueller Confirms She and Kids Are HIV Negative After Actor's Interview
"It's hard to be a drug addict and be HIV positive and do 40 [episodes] a year," Mosko allegedly wrote of Sheen and his work on the FX sitcom Anger Management in a private correspondence sent in March 2014.
Sheen has publicly struggled with substance abuse problems for years, and has spent several stints in rehab facilities.
Sheen recently made headlines when he was forcibly ejected from Hennessey's Tavern in Dana Point, California, after security escorted him out of the establishment in a headlock after behaving disruptively in the dining room.
PHOTOS: Charlie Sheen Through the Years
His history of peculiar behavior began in 2011, when the Golden Globe winner publicly and repeatedly insulted Two and a Half Men creator and executive producer Chuck Lorre, while Sheen was still a cast member on the show. Sheen was subsequently dismissed, and his character killed off, which marked the start of his highly publicized "meltdown," including erratic behavior and unintelligible interviews.
Sheen's tumultuous relationships with his ex-wives and girlfriends have often been the subject of tabloid scrutiny, including his numerous relationships with adult film actresses.
In the 1990s, Sheen famously dated adult film stars Ginger Lynn and Heather Hunter. In 2011, Sheen began a relationship with former adult film actress Bree Olson, whom he called one of his "goddesses."
They reportedly lived together in 2011. Olson announced her retirement from adult films and also left Sheen later that year.
MORE: Bree Olson Claims She Learned of Charlie Sheen HIV Diagnosis via Media
In a 2013 interview with Piers Morgan, Sheen said that he was dating Penthouse model Georgia Jones, and in February 2014 Sheen revealed that he and adult film actress Scottine Ross had gotten engaged. However, they called off the engagement in November of that year.
Sheen has also been married three times. Sheen's first marriage to Donna Peele, which began in 1995, came to an end a year later when Sheen was named as an alleged client of Heidi Fleiss' escort agency.
Sheen and actress Denise Richards, who share two kids -- 11-year-old daughter Sam and 10-year-old daughter Lola -- tied the knot in June 2002. Richards filed for divorce in March 2005, accusing Sheen of abusing alcohol and making threats against her. Their divorce was finalized the next year.
WATCH: Source -- Denise Richards and Her Kids Not HIV Positive
Sheen then tied the knot with actress Brook Mueller in May 2008, and welcomed twin sons Bob and Max in March 2009. Sheen filed for divorce in November 2010. The next year, Mueller reportedly obtained a restraining order against Sheen and social services removed Bob and Max from Sheen's home. Sheen and Mueller's divorce became final in May 2011.
Sheen is also the father of a 30-year-old daughter, Cassandra, from his relationship with his former high school girlfriend Paula Profit.
OP-ED: Charlie Sheen Doesn't Deserve HIV Any More Than I Did at Age 11
In the wake of reports regarding Sheen's HIV status, Olson, Sheen's former "goddess," took to Twitter on Monday to address the situation, and stressed that she's free of all STDs.
"There are speculations circling that one of my ex boyfriends from years ago may have contracted the HIV virus," Bree wrote. "They are rumors and I know nothing more than anyone else."
"I, myself - have been to the gynecologist once a year since we split up and have always been tested across the board for everything and have come back clean across the board every time," Olson continued. "For all the 'news' sources out there, leave me alone."
RELATED: Charlie Sheen Goes on Twitter Rampage Against Ex-Wife Denise Richards
Sheen has on multiple occasions ranted publicly about his ex-wives -- most recently in June when Sheen went on a lengthy Father’s Day tirade in which he called Richards "a shake down piece of s**t doosh phace" and an "evil terrorist sack of landfill rash." Sheen also called Richards the "worst mom alive."
Sheen allegedly missed seeing his children so that he could take a trip to Mexico, according to tweets posted by Richards in response.
On Monday, a source told ET that Richards -- and the couple's two kids -- are HIV negative. A rep for Mueller released a statement, after Sheen’s interview with Lauer, that she and her children are HIV negative as well.
Sheen said on Today that both Richards and his other ex-wife, Brooke Mueller, are aware of his HIV status. The actor said he recently told his oldest daughter, Cassandra, of his diagnosis, but has not shared the news with his younger children.
Sheen's ex-girlfriend, Mia Isabella, told ET exclusively that she's praying for the actor. "That is hard news to hear I'm saddened but know him as an incredible person and advocate," Isabella said. "My memories of him reflect a warrior and super brave person so I know he will navigate through this with strength. He isn't afraid of facing any public scrutiny and speaking frankly and I have nothing but admiration for his friendship."
Sheen's former Spin City co-star, Heather Locklear, showed her support for the actor via Instagram on Monday, writing: "My heart hurts. Prayers for Charlie and his family."
Watch the video below for more of Sheen's HIV revelation.