So.... did you break up for real already? Or are planning to? You don't sound sure. GET sure.
If you already broke up, be broken up! Cut off all contact. No phone, not email, etc. Occupy your free time with your other friends, other interests, get involved in the community, etc.
If you have not broken up yet and plan to and are worried how to do it without getting sucked back in by the lies... nobody said you have to break up in person. Write the formal "I am breaking up with you" note or email. Maybe that helps make it real to YOU. Maybe you need to use the actual words instead of "OK but next time will be your last" vagueness. Because if you took him back in the past, he's not believing you.
Or just decide it is over, cut off all contact, and let him come to the conclusion for himself!
Or if he's into the emotional abuse trip, and you feel weak and hurt right now... know he's gonna try to sweet talk you back. Learn the cycle, and don't get sucked back in.
http://www.lilaclane.com/relationships/emotional-abuse/
Or if he's some kind of emotional vampire draining you... learn to combat it.
http://www.albernstein.com/id55.htm
If you see his email -- delete without even opening. Get caller ID, change your phone -- whatever so you don't have to pick up and it is him. Do not facebook or any of that.
Life isn't all about win or lose type choices. Sometimes it it this choice stinks (breaking up) and this choice stinks too (not breaking up and endless drama). Then you pick the least stinky of the two, and it sounds like you pick breaking up.
Do it fast like ripping off a bandaid. It will hurt at first but get it over. Then the stink (him and his lies) can go away faster and you can feel better.
You will go through the stages of grief for the loss of the relationship, even if it was good that you broke up with him. Allow yourself to feel what you feel, but don't be afraid to feel it. It's part of the clearing the air. And when you can see clearer and breathe better you will realize -- Hey! This is not so bad! I'm liking it!
Hang in there.
GL!
A.