T/W: abuse and s/a

So over a year ago I was in a 3 year long relationship with an abusive ex, which included physical, emotional and sexual abuse. Since that relationship, I’ve met an amazing guy and I truly picture myself marrying him. 

The only issue is sometimes my past issues take over my mind and I get absolutely terrified of him. I know he would never hurt me or do anything to harm me, and he’s the most supportive guy I’ve ever met, but I get into this headspace where I think he’s going to hit me or punch me and I get scared when he comes near me, even when I know he’s coming to comfort me. 

How can I get past this mental block??