How to deal with past relationships and mistakes?

I’m currently in a relationship with a guy I’ve known for 3 years now. We’ve been dating for about 1 1/2 years, and we’ve gone through so much. So before him and I dated I went through a rough patch and had terrible friends that were really bad influences. When him and I started dating I started to realize what kind of person I was becoming and I didn’t like it, so I started to fix my ways. It took some time but rather enough I finally became my true self again. But, when I decided to change I wanted to leave all the other stuff behind. I didn’t tell my boyfriend about my past and the full truth behind some situations. He thought I’d always been this good girl because that’s how I seemed and when I finally told him about how many guys I talked to during the summer before him and I started dating he got upset because I’d lied to him. He also got upset because he’d found out ( I told him) that I told my ex boyfriend, who I dated in middle school, that I loved him and I talked to that same ex during the summer before him and I dated so idk, I know I messed up. I’ve changed though so much, I’ve grown as a person and I want to let all of that go. He brought that stuff up today after us being amazingly great for a while now and he got upset because he thinks I’m lying about some of the stuff he asked and I’m not. Idk what to do or how to prove to him that none of that matters and that I’m not lying to him. Please help, I love him even through our rough patches he’s who I want to be with and I want to fix this between us.