What should I do about this guy?

He isnt technically my boyfriend, we have been on and off for about 2 years. 3 months ago he told me he still loved me for the first time in a year. He said he wanted to date me again, but that we should gain self confidence and learn to be emotionally stable first. Basically we decided we would try to get along better and not accuse eachother so that we could date again, we also agreed to not find other people, that we were almost dating so if we hooked up with someone else it would feel like cheating. Well things were going pretty good. I went to Hawaii for a week and got back today. But before i left i was kind of paranoid that he might find someone else (unintentionally). I tried to trust him as much as i could even though he lied to me before when we were ONLY friends. A few times when i called him from hawaii he was at work and instead of telling me nicely, he would say "im working damnit why cant u respect me". I knew something was going on. Well thursday my best friend(who hates this guy) told me she saw him with another girl at the mall looking at movie times a few days before and that shes been meaning to call me about it but didnt want to ruin my trip. I asked him about it and he denied it. I can tell something is going on because he is SO angry with me when i dont do anything wrong. i call and he has to go within 3 minutes. He told me "one more chance to be nice or we are done" Well accused him of liking someone else so now he thinks we should just be friends or something. I dont want to talk to him anymore, i cant stand this. even though we werent dating it hurts just as bad. i cant bring myself to leave him alone and not call and wonder what hes doing. How do i get over this? Or do you think he is lying? The only proof i have is my friend told me. He doesnt seem to care that this is the end though, if he doesnt admit to it. and he wont admit to it. All this time i was worried about going to hawaii and what he would do, i accused him of doing stuff, then my friend calls me about it and he acts so different around me. Something is OBVIOUSLY going on. what should i do?? I want him to care but at the same time he is no good for me. He also said, "i dont wanna date you right now cause you accuse me to much, but i promise i wont find anyone else, ill wait for you to change." its almost like he led me on this whole time til he could find someone else. Even though i really think he meant it when he said he loved me and everything. Maybe I pushed him away?