HIV spread quickly in the gay community because the skin in the anal passage is a lot thinner than the skin in the vagina, thus more likely to tear and provide the virus entry into the bloodstream. It isn't personal.
But on the positive side there is a lot more social acceptance nowadays - look what happened to Alan Turing in the pre-aids era.
I'm sorry you have to face an aids diagnosis. Life really can be cruel and unfair, and so can people.
No reason, this world kills without a thought. A century ago you and your mother would be lucky just to survive childbirth