I just can't trust my ex around my friends!

I just can't trust my ex around my friends!

Dear Diana,
I was committed to and was madly in love with this one girl. We were together and happy for five months and I thought it was one of those relationships that would last. I introduced her to all my friends and also to my

family members. I, one day, sensed that she was hiding something from me and asked her to tell me what it was. She said she was in love with another guy as well but that she really loves me. It was one of the biggest shocks of my life. I tried to get past it but wasn't able to trust her at all. I decided to break it off with her, just be friends and move on with life. But she cried about wanting to be with me. I even stopped talking to her so she would forget me. A couple of my close childhood friends went to console her. I was okay with it, because she hardly had any friends. In time, she started talking to almost all my friends. Some avoid talking to me but are still meeting her. She started talking to one of my very close friends, who asked me to at least keep in touch with her. I did so. They are now constantly in touch with each other. They speak till very late. They go for walks together. I asked my friend if he is carrying on with her.u00a0 How do I free myself of this sick mindset? Was it a mistake to introduce her to all my friends? I don't want to lose my friend at any cost.