TW: Cutting, Suicide, Emotional abuse

I just want some responses so I have some people to talk to because as a guy I don’t really have anyone to go to. 

Problem: I haven’t liked someone since I got my emotions back properly and now that I do I’m scared. 

Context: My first girlfriend and I “loved” each other but cracks showed quickly and I was naive. We weren’t compatible at all. We stayed together for 8 months and this ruined me. I was pretty happy and ignorant before. 
She exposed me to the worst side of everything. She had problems. She cut herself, she had bad self image and fished for compliments, and one time when we got in an argument she admitted to being suicidal. I being 15 at the time was emotionally distraught and destroyed as a person. I don’t think I will ever fully recover from the emotional torment I went through. 
If you’ve been in a relationship like this you know what I mean when I say you’ll never lose feelings for them. 

What is the big problem here: I am talking to a friend of mine who I now fancy. She’s pretty, outgoing, and just super nice to be around. But, After the first relationship I didn’t feel anything for 2 years or so. Nothing. I still struggle with DP/DR,  existentialism and even suicidal thoughts because of this. I haven’t had problems with these except for now. Talking to this girl has given me crazy anxiety, over thinking, trying to hard, getting excited when she messages, and trying to play games to get her to like me too. I haven’t come forwards in fear of losing my only friend group and I don’t know if I ever will. 

Just talk to me. I don’t have anyone close.