Advice

I've been in a long distance relationship with my boyfriend for almost a year now. Before we started officially dating we were talking and "exclusive" meaning we agreed we wouldn't do anything with anyone else. I recently found out a lot of things from the past, while we were dating and before. The stuff from before although hurt me a little bit I can let go of because technically we were not dating (he was hooking up with people).  However during the time we have been dating I found out he has 1. been on tinder talking to girls 2. sending girls DMs on Instagram getting their numbers and asking them to hang out 3. saw conversations on his phone asking one of his girlfriends to hook him up with one of her friends. I forgave him for all of this (stupid I know) and he kept insisting he never "physically" did anything with anyone. Then I find out that months ago he kissed a girl and danced with her at the club. I forgave him because he seemed to regret why he had done in the past, he said he would change and I do believe him. He has showed me I can trust him NOW.  Do you guys think that after what he did it is possible to change? My problem is that everything I know I found out in my own and also that during the time he was doing all this he was the same with me always sweet always nice, really made me think he loved me.