As a background, I was with a girl for five months before she broke it off after I slacked off a bit. We remained going back-and-forth in a grey area where we were acting as if we were in a relationship.
She broke things off twice more, with the last time happening a few weeks ago. I know that a relationship with her is not good for my mental health.

I had finally resolved that it was over and I began to move on. I had just done so when she asked me to come to her place for dinner. It was fine, nothing came out of it until the next day. She asked why I broke her heart and began to cry.

She then began to tell me that all she ever wanted was to be my girl, that she has always loved me from the bottom of her heart and that she can't bear the fact that I had moved on. I left the house and went back home because of a doctor's appointment.

Later on we had a long phone conversation where she eventually forced me to say that I didn't want to be with her. I could tell that it was devastating, we both cried and I felt so awful for doing it. She called again twice more and asked me to say that it wasn't true. She said how I'm the only one she has wanted to marry and have children with (but we're both only 23). She is a very emotional person with a long history of issues. I can't stand to see her sad.

Her trump card was that if I have moved on then she never wants to see me again. I don't want that to happen. I want to be friends with her because she has meant so much to me regardless of the relatnionship. I am best friends with her older sister as well and I don't want to lose her either.

Eventually, against every single fibre of my being I said that I will give it another chance. I do wish that it could have worked but I was so confident that it hadn't and that it was over. I was just hurting so much and I wanted to make her feel better.

Now I'm stuck in a position where I am with her again out of guilt. I can't just turn around now and change my mind after all that has happened. I am looking for every excuse to find a way to end it. I am so angry at myself for once again putting my mental health on the line.

My parents don't know that I have taken her back and I'm terrified to tell them because they will be very angry that I didn't let go. It will take too much energy to deceive them. I know that my guilt will only increase if I decide to break up with her in the future.