Why can i not sleep with someone i care about?

It's not imtimacy issues. It's guilt issues. Not judging, but for starter, stop getting drunk and sleeping around, or you will get a STD and give it to someone you DO care about. Secondly, until you stop and deal with the "past", yes intimacy is difficult with someone you care about. You are afraid they will find out about the past and be angry or judge you. So it has to be someone you care about enough to be honest with BEFORE and fill them in on your past (details not required, just general is sufficient). If they still care about you and accept you then, you will suddenly have no problems being close to/with them ually. Get comfortable in your own skin first, and don't be afraid of being alone. In fact, embrace it for a while. Then things get better with relationships.