Friends, friends with benefits, or more?

My best guy friend and i have been friends since we were in 5th grade (were seniors now) and from then until now we have always had on and off feelings for each other. He used to have the biggest crush on me when we were younger, and i didnt start really liking him until a few years ago. From then on i told him how i felt, and we tried being friends with benefits/dating because he didnt want to be in a relationship because they usually end with no friendship or anything in the end and he didnt want to lose me, but we always wanted to kiss each-other and such. So after tryin FWB's for a while he somehow stopped talking to me and told me that he was just too busy. so we stopped talking for a while and then about a half-year later we started talking again and the whole thing would start again. FWB's and then i started to like him a lot but he still didnt want a relationship so we eventually stopped talking again. this went on and off for a while and then a couple of months ago we started talking for good again and things were going great. we got really really close and pretty serious, and then one night things got real serious and he stopped talking to me again. now we barley talk and he just tells me that hes too busy again. i asked him if i do something wrong but he said no, and before he would always tell me that i made him so happy, and that hes liked me for forever and has always wanted more with me. but what i dont understand is why he always tells me hes too busy, and why it never works out. i try to ask him but he never really gives me an answer & im tired of bothering him. help! i miss him and i just want things to go back to the way they used to be!