He’s hiding something.

I️ don’t want to post this for attention but mainly because I’m nervous. My boyfriend and I have been together for 3.5 years now. And in the first year of dating I️ started realizing he had a lot of attention to other girls which only made me nervous. I️ ended of finding out he was talking to a stripper friend of his saying that he wanted to see her and do sexual things with her. After this I️ obviously distances myself and told him how I️ felt. A while later I️ found girls underwear and his story changed every time I️ asked where it was from. He deleted messages from girls and when we went on a break he finally realized what had happened and tried fixing it but now he’s hiding his phone again and it doesn’t feel like I️ mean much to him. What should I️ do? In desperate need of help. I️ love him and I️ believe he really wants to change but I don’t know...