PROBLEM WITH TRUST...PLEEEASE give me an opinion?

SORRY SO LONG......My boyfriend & i have been together for about a year and a few months...a few months ago me and him got into a huuge fight over me hanging out with my ex. he accused me of cheating (which i did not, i just hung out with him as a friend) and he ended up breaking it off with me. i was super heartbroken. well we ended up talking things out and we got back together. A month later he ended it again because we had become so distant (i think due to unresolved problems about the whole situation with my ex) we remained friends but we ended up getting back together. about a month & a half ago he broke up with me AGAIN because he felt as though our relationship was getting in the way of both our lives (which was tru in a sense because we had a tendancy to stop doing the things we needed to do in order to hang out with eachother, but i would have preffered to work it out). he still wanted to maintain our friendship because weve always been best friends but i told him until i could get over him that we should stop communication for a while. that lasted about a week then he called me one night & told me he was stupid, & that he didnt realize wat he had until i left. after that i agreed we could work on things. so were together again & hes been great but now i find myself trying not to feel too attached out of fear that he'll leave again =/ trust is a huge thing for me so this really sucks. ive tlkd to him abt it & he tells me he was just afraid because ive been his most serious relationship & hes never been in love but he swears it wont happen again & that he'll prove it. Hes been incredible but im still scepticle =(....what are you thoughts?