"I am here to admit that I am, in fact, HIV-positive. I have to put a stop to this mirage of attacks of sub-truths and very harmful and mercurial stories that are about me that are threatening the health of so many others," Charlie Sheen told Matt Lauer this morning on the Today Show.

Various reports confirmed on Monday that Sheen, 50, had been diagnosed as HIV-positive four years ago; late in the day, it was confirmed the actor would appear on the Today Show this morning to make a "personal announcement."

"It started with what I thought was this series of crushing headaches and migraines and sweating the bed. I thought I had a brain tumor. After a spinal test, they said, this is what's going on . . . It's a turning point in one's life," Sheen said.

According to the actor, he has been extorted by some of those with whom he's had sex. "I've paid those people," he laughed; "Not that many but enough that it's depleted the [bank]. . . Enough to bring into the millions . . . For some reason, I trusted them. They were deep in my inner circle, and I thought that they could be helpful. Instead, my trust turned to their treason. We're talking about shakedowns ... One of the prostitutes threatened to sell the [medication] to the tabloids . . . It was after she had spent the day after she had helped me with herbal medications," he told Lauer. "I was so depressed by the condition that I was in . . . I was making bad decisions."

Sheen admitted he had unprotected sex with two people after his learning of his HIV-positive status, but says they are now under the care of his doctor. "Yes, but the two people that I did that with were under the care of my doctor, and they were completely warned ahead of time," the actor said.

Sheen says he'll no longer be a slave to those extorting him: "Not after today, I'm not. That's my goal, that's not my only goal. I think I release myself from this prison today."

Sheen claims that the HIV is now undetectable in his body and his doctor supports him: "Charlie does not have AIDS . . . He is healthy; he does not have AIDS."

Stay tuned for more; it's doubtful this will be the last time we hear from Charlie ...