I REALLY need your advise!?

I'm not ping judgement, this is just my opinion. But if you really cared about this person, *really* cared then you wouldn't think about another guy let alone sleep with him. Truth is you cheated on him - you were unfaithful and it's your own fault. Admit your guilt to him because all lies will be revealed at some point. If he is willing to take you back, awesome. If not, you will have to move on, find somebody else and learn your lesson that people and feelings are not to be played with. Good luck =)