Angela is her name

I met her in 7th grade. We had gym together, she was with someone at that time. I had her for a class in 8th grade, we sat next to each other the whole year and became good friends. In 9th grade I asked her out. We were on and off most of the year. Stuff happened, she went back to an ex, I started dating someone else. She ended it with her ex, while I was with the new girl she would tell me how she was sorry and she wanted to be with me. I dated the other girl for about a month, when we broke up, I told Angela and basically started dating that same day. This was summer going to 10th grade. We dated about a year and 6 months, I broke up with her, the first time I broke up with her, all the other times she had done it. Months after that we continued to talk/hangout/text anyway. We remained broken up. It's now senior year, she tries moving on and starts dating, I started dating too. I start going out with another girl for about 6 months, we break up. I start talking more to Angela, since we actually have a class together, we hang out again, and I still have feeling for her. We talk for about two months, and the girl that I dated for 6 months says she misses me, and we'll I still missed her too, so get back with her. Angela is hurt, again. I had been asking her to break up with the guy she was dating, those two months we were talking again, and she was going to when he got back from basic. So I start dating that girl again, for another 6 months, for those 6 months Angela and I are doing things behind the people we were dating and it didn't stop until the end of summer when her boyfriend came back. I continue dating this girl and she continues dating this guy. Dating that girl again was the biggest mistake of my life, the relationship was so toxic the second time, I was putting all the effort and didn't feel anything back, everything was for that girl but she just ended it for unknown reason. And I started to know what I had done to Angela. I should have stayed with Angela, I was given the chance but I didn't take it. I realized that that was who I was suppose to be with and how much she loved me and how much I hurt her. I put her through so much. And I feel so horrible about it and I wish I could tell her how sorry I am.

She is engaged to that guy...