I think there are two different issues going on here.
Firstly the fact your taking drugs and the health issues that go with that.
But secondly, that you feel you need something to enable you to sleep with guys.
By the fact that your emphasising guys can i ask if you've ever been with a girl? Because it may well be that your questioning your sexuality.
I've always struggled to enjoy sex, and a while ago would simply get myself totally drunk to be able to do it. For me it was very low self-esteem. The thought of someone seeing me, touching me just made me feel so bad that i drank to get rid of it.
All i can really suggest is you try to look more into why you feel you need the drugs? Are you with a boyfriend you can talk with? Are you feelign pressured into it? Is it self-esteem.
Working that out should enable you to work on the root difficulties.
In terms of the drug use. It is dangerous. You need to stop, or get help for it.
Hope i've helped a bit x