I need my boyfriend to be back to how he was

Okay so my problem is that, I was dating my best friend few months ago and then he left me for some girl in his class. I was so in love with them that I never actually stopped talking to him.. There were times when he used to visit my place and showed me...

those feelings all over again.. and then one day he left to India and I found out that he started dating someone else over there too. I was so deserted and pissed at him that I screamt at him and asked him to leave me alone. he started to see teh changes in me and then he asked me to date a guy who really liked me from quite a long time. I started to date this other guy and my best friend was really jealous because I wouldn't give him my time at all. and then one day when I couldn't take it anymore I brokeup with the other guy because I felt I was using him to get over my best friends. and few months later my best friend asked me out again. he told me he started to value me and stuff like that.. he did things that he never would have done for anyone. and then I lost my virginity to him. but I was still confused if I loved him or not. and now when im so clear about things that I love him really very much, hes started to change back to how he was. he stopped smoking for me but has started again because he got to know I went physical with my ex. and now he behaves like he doesnt give a shit about me. we are still ina relationship, but we fight every day and the breakup topics comes in every fight.
PLEASE TELL ME WHAT TO DO?
I really need your help, because I don't wanna lose this guy AGAIN!