Don’t know what to do

my boyfriend. I feel like I can’t talk to him about anything anymore. but I still love him and want try to make it work.

I feel like I can’t trust him because we both have different views on cheating. He thinks kissing another person when your far away from girl friend is ok not cheating I think it is. Don’t think he has kissed anyone else but not completely sure. We haven’t had really any fun like laughing around goofing off fun together since August because we are both so busy. But when I see him with his friends and we are all hanging out they are having fun. Why can’t I laugh and be goofy with them? Have I just become heartless? That I just can’t have any fun anymore? Even when we are by are selfs it seems like I just can’t goof around and have fun. What should I do?