I feel terrible about myself

So I’m in a new relationship with this guy. He’s one of the nicest and most caring guys I’ve ever met. He’s so different but in a very good way. I’ve never had a guy treat me so nice before. But I have a pretty bad past. I used to have a super low self esteem and I felt alone in my life. So I ended up sleeping around a little (but with people I knew). I never caught an std, I’m 100% clean, I don’t have any kids, and my body count is not above 20. I’ve changed so much and all of this has ended well over 2 years ago. I feel like I don’t deserve this guy and I feel like if he found out or if I told him he’d leave me and I don’t want that. I just feel so bad about myself and I feel gross.