HIV didn't come about because of unsafe sex, it was a freak accident involving blood. And as far as I can tell, in the history of modern humans there have been three STDs that have been life-threatening: Siphilis, HPV and HIV. So I wouldn't worry too much.

Remeber that unsafe sex is the natural norm, especially if you don't have to worry about unwanted pregnancy (as in the case of gay people). Safe sex only truly became a necessity because of HIV, an extremely recent phenomenon.