New relation brings up old negative feelings

I was in an emotionally abusive relationship for 12 years. I left that about two years ago. I’ve been healing pretty good, I’ve become more confident, stopped feeling anxious and depressed, adopted a healthy lifestyle and taken up contact with my old friends. Some time ago I also met a new partner. I felt like I was ready for that but now I’m not sure anymore because those old feelings are coming back. I realize that it probably would be a good thing to talk with my partner about my feelings, whatever it leads to, but I don’t know how to do that. I’ve talked very little to anyone about what happened in my previous relationship and I don’t really want to talk about it either, or even think about it. I guess therapy is an option for some people but I feel I don’t want to talk about it with a therapist either. Don’t really know what to do at this point.