Tony Green admits he fell into a "conspiracy trap" that led to the deaths of two members of his family.
The Texas-based Donald Trump supporter has come full circle after previously labelling COVID-19 a "scamdemic" - a phrase he picked up in his dealings with "radical and rowdy cult followers" online.
Mr Green wrote about "family tragedy" in an open and honest blog after his father-in-law and his father-in-law's mother fell victim to the coronavirus - and he himself barely survived.
He says he was a "hard ass that stood up for" his "God-given rights" when he threw a party that sparked a massive cluster event and killed his loved ones.
"I admit I voted for Donald Trump in 2016," he wrote. "I admit travelling deep into the conspiracy trap over COVID-19. All the defiant behaviour of Trump's more radical and rowdy cult followers, I participated.
"I was a hard ass that stood up for my 'God-given rights'. In great haste, I began prognosticating the alphabet soup about this 'scamdemic'. I believed the virus to be a hoax.
"I believed the mainstream media and the Democrats were using it to create panic, crash the economy and destroy Trump's chances at re-election."
With those thoughts in mind, Mr Green threw a party on June 13. The next day, he woke up sick. Two days later, his partner was sick and his parents were sick. Then the in-laws came to town and the spread got worse.
"They brought (my partner's) mother and one of my partner's sisters," he said. "That night my father-in-law became ill. Then my mother-in-law and their daughter began feeling sick. They cut their trip short.
"Two days later, my father-in-law's mother got sick. The new mommy and daddy got sick too. We all tested positive for COVID-19. Only the newborn was spared."
Mr Green and his father-in-law were admitted to hospital. His father-in-law and his father-in-law's mother both died. He was lucky to survive.
"The virus attacked my central nervous system and the staff stopped me from having a stroke," Mr Green said.
While he is healthy now but cannot shake the guilt from the party that started it all.
"You cannot imagine the guilt I feel, hosting the gathering that caused so much suffering," he said.
"Having been a denier, carelessly shuffling through this pandemic, making fun of those wearing masks and social distancing leads me to believe; my actions convinced both our families it was safe when it wasn't.
"For those who deny the virus exists or downplay the severity of this virus; it is very real and extremely contagious. Before knowing you have it you've passed it along to your friends, family, co-workers and neighbours. Husbands, wives, and children are being separated.
"The sick taking care of the sick while those without symptoms are self-quarantining. I am aware of how my bias could discredit me with some, but trust me, you do not want this virus.
"And you do not want your loved ones suffering and dying from this because you are taking a political stand or protecting the economy over what may be their life next. We are all at the precipice of a common heartache."
In an interview with CNN's Anderson Cooper on Monday, Mr Green said he wanted to set an example to others.
"We have to be the example to, I guess, bring awareness (of what can happen at a small gathering)," he said.
Writing of his struggle, he said the pain the virus caused him was unbearable.
"Imagine the sound and vibration of an old-fashioned electric heater going through your whole body. Imagine gasping for air with every step you take," Mr Green said.
"Imagine rubbing icy hot all over your head to soothe a painful headache. Imagine your eyes in a bowl of water while your still seeing through them. Imagine collapsing and waking up in the ER only to find out COVID-19 attacked your central nervous system and the doctor had just saved you from a stroke.
"If that were the worst of it, it would be bad enough. The sequence of events (that followed) are the unimaginable details of a family's harrowing plight with COVID-19."
He said Americans must understand that "this is not going to go away without sacrifice".
"Either way, we are going to pay a price … To do nothing is to be foolish. To ignore or question the validity of this virus, its contagion, or the consequences of selfish attitudes at this stage is completely stupid. I am calling myself out first.
"I was 50/50, but it was not personal then like it is now. I fell on my sword. If we continue being more worried about the disruption to our lives than we are at stopping this virus, listen to me, not one American will be spared."
Originally published as COVID denier's party kills own family