I miss my ex boyfriend and I don't know how to deal with it?

He broke up with me 3 months ago. We were together for over 5 years. We got along great, had a lot in common and were best friends. Then one day he came over and broke up with me, out of nowhere. From the day he broke up with me he has said that he wanted to stay friends with me, and I have seen him a couple of times since the breakup. He never really told me why he broke up with me, but I am guessing that it has something to do with his family. They control his life and it's sad. Anyway, I still love him so much and I miss him a lot. I try to keep myself busy so that I won't think about him, but so many things that I see and do remind me of him. I am not sure how he feels about me, although after he broke up with me, a few weeks later he told me that he misses me and that he still loved me. Not sure how he feels now. However, he still texts me nightly to say good night, either saying "goodnight baby" or "good night! Mwah!" The couple of time that we have hung out, he seems so happy to be around me and he acts like himself. He would always hug me and even asked to kiss me, but I always said no. The way he hugged me was not the way you would hug a friend, it was a long, close hug. Anyway, I haven't seen him in a while and I try not to reply to his messages or calls, but if I don't, he will start asking me why I am ignoring him, if I am dating someone else, etc. This past weekend he asked me to go see a movie with him. I already had plans so I messaged him back and said no, sorry I have plans already. He immediately called me, however I had my phone in my purse and was at the mall, so I didn't hear it ring. He called 5 times and left a voice mail asking me why I was ignoring him and what plans I had. He also sent me 3 messages asking the same thing. The way he is acting makes me think he isn't over me, but who knows. I definitely am not over him and it seems to get harder each day. I have been crying for the past hour. I blame myself for the breakup, even though I don't even know what caused it. I wish I could just go back to 3 months ago and undo whatever it is that made him not like me anymore. How do I deal with this??