Bree Olson: Thanks a Lot, Charlie Sheen ... Now People Think I'm Spreading HIV!

Charlie Sheen's HIV announcement is blowing up in the face of his ex-girlfriend Bree Olson ... who's getting blasted by haters, and harassed by exes who think she infected them.

Bree tells TMZ she's shocked at how much hatred and vitriol has been directed at her, while Charlie's getting all the sympathy. One tweet -- "You're a ho! I wish you would've contracted HIV" -- is just an example of the backlash she's getting.

Meanwhile, Charlie's being hailed as brave and a hero.

Bree says multiple ex-bfs contacted her right after her 'Howard Stern Show' interview ... worried they might test positive. She stresses that she has never tested positive -- but understands the guys are "just reacting out of emotion. They are angry just as I am angry."

While Charlie insists he never knew he was HIV positive when he slept with Bree ... she says he NEVER called to give her a heads-up, even though they frequently had unprotected sex. Also, as we reported ... Charlie even admits he was diagnosed just TWO weeks after they broke up.