found out a month later

Hi girls. I need some help. My boyfriend and I broke like a little bit more than a month ago. We broke for a span of 2 days. The day after we broke up, he got drunk and kissed his ex gf . Then the day after that he told me he missed me and wanted me back. I took him back. I truly love him, I do. But I just found out about this today. I confronted him about it and he admitted it. What bothers me is that he lied to me when I asked him if he did anything w anybody in those 2 days and he said no, nothing. He kept saying that it wasn't really cheating Bc we were broken up & I get that but it hurts ya know? He told me there were no feelings there and that he loves me. I forgave him & i told him I was willing to forgive and forget. But now I'm confused... idk if that was the right thing to do because now I don't think I can trust him or believe him... can someone plz give me some advice? THANK YOU!