"This is so unfair...there's not enough words to express the hole left in everyone's hearts. I can't believe this is life now. I don't know if I'll ever believe it," he wrote in a lengthy Instagram post on Saturday. You were just here... We were just in the back swimming with Josey the day before. Life just isn't fair. I don't know what to say."
He continued by adding that he's thankful for their time together and that their journey "gave us the sweetest and kindest smart little boy we could ever hope for."
He added that she would get "annoyed" that he would snap so many photos and videos of her and their son, Josey, but now he will have something to show him when he gets older.
"Life is all about good times and bad times but with Josey it makes the bad a little less so because a part of you will always be with us. He'll never forget where he came from. We miss you. We will always love you. Love you Meep. ???," he concluded, before thanking everyone who has reached out to him and their family.
Rivera and Dorsey were married from 2014 to 2018. They share a 4-year-old son, Josey, who was found alone on a boat on Lake Piru in Ventura County, California, when Rivera went missing on July 8.
The 33-year-old actress's body was recovered from the lake on July 13, and during a news conference that afternoon, Ventura County Sheriff Bill Ayub shared what authorities believe led to Rivera's death.
"We know from speaking with her son that he and Naya swam in the lake together at some point during their journey. It was during that time that her son described being helped into the boat by Naya, who boosted him onto the deck from behind," the sheriff said. "He told investigators that he looked back and saw her disappear under the surface of the water."
Police believe Rivera disappeared mid-afternoon, when "there are a lot of currents on the lake."
Ayub also shared the working theory of what may have happened the day she went missing: "The idea perhaps being that the boat started drifting, it was unanchored, and that she mustered enough energy to get her son back onto the boat, but not enough to save herself."
The sheriff further noted that there is no evidence of foul play or suicide. An autopsy was later performed at the Ventura County Medical Examiner’s Office, where Rivera's body was identified based on dental records, and the cause of death was determined to be drowning by accident.