Okay... time to move on and learn from this so-called relationship. As "Outspoken" mentioned before me, it was a very toxic situation leading in a downward spiral of guilt, confusion, betrayal, and immaturity. You are young so immaturity is natural for your age but in the future you don't need to continue in the same pattern.
Cut him loose. Learn from what was wrong causing you pain and frustration. Love and respect yourself enough to face the future without a poisonous relationship. Then Live, Love, and Laugh.
Before you move into another relationship, talk to a counselor at church or another mature and trustworthy source (they have free counseling in many churches) and heal spiritually, emotionally, and psychologically. Best of all good things to you.
Toxic drama addicts! Honey from your little summation of on again off again almost relationship first it appears to me you were not and never did get what you need and want from this relationship. If you were then you would never be even contemplating straying to point sex would be possible. He seems two practice that big old double standard.It is okay for him to be unfaithful but your transgression makes you unfit to be his partner. Who died and made him God? To much of the bad!Not enough of the good! I say run Forrest run! Believe me you have wasted enough time, energy and emotion on a guy that holds himself and his actions above you. The pain will go away and this will be but a bump in the road to the relationships, breakups that are on the way to finding the right partner some where out there in your future.
Assuming he broke up with you and not vice-versa, take some time to take a hard and honest look at what went wrong.
Give him space while you do this. Drop out of sight, in other words, so he'll wonder where you went. But don't just duck and cover. Really come to grips with where THINGS (not you) got off track. Once you've done that, and some time has gone by, get in touch with him and let him know that, even though it's difficult, you agree with the decision -- that it's for the best. Tell him that you regret your part of that and that you hope the two of you can be friends in the future, just not in a romantic or sexual sense any more.
None of this will be what he is expecting. He'll be expecting you to try to strong-arm him into going back on his decision. Because your actions have completely taken him by surprise, he will start wondering if he misjudged the situation. At that point, he may want to start things up with you again. If that happens, take it slow and take steps to avoid repeating the problems that led to the breakup in the first place.
Is he rich, insanely endowed, or an absolute sweetheart who takes care of business? If the answer is no, move on and find someone new.
So is he? I actually posted an answer before I saw there was a whole wall of text posted describing the relationship. To be fair, I did not have time to read all that text, but I take it the only bulge this guy has is the one made by his wallet. Am I right?