Terrified because he is treating me too well?

A few months ago, I got out of a very mentally abusive relationship. We tried to work it out up until the point I found pictures of him kissing another girl.

Shortly after I stopped all forms of communication with him, I met someone new. He is the sweetest and most amazing guy I have ever met. He has treated me better than my ex ever has.

And this is scary for me. I'm not use to being in a 'healthy' relationship.

We talked a lot about my past relationship and he understands, but I'm terrified of being in such a good relationship.

I don't know if these feelings or normal.