<human>: So I've been dating this girl for 2.5 years, and in March of this year I decided to leave her because she has EXCESSIVE trust issues which often lead to her immediately initiating an argument and going beyond what is reasonable to ensure I was faithful. We lived together for about a year and we were very supportive of each other's ambitions. It was a pretty bad break up but she was still trying to get me back. I, knowing that she was trying to change, gave her a chance over a few months to prove to me that she at least showed progress in changing and committed myself to her throughout that time. After my 2 month long army training in the summer, I decided to give her another shot in August upon my return. Not even a month into it she quickly reverts to her previous state and I broke it off again in an argument. Within 3 weeks she slept with 3 guys trying to get back at me (slept with my no longer best friend) with two of three being from POF. Before I found out about her activities, I suddenly came to the realization that I REALLY love this girl and HAVE to win her back. She admitted everything to me and even after that I still wanted to be with her. She says she wants to give her last "one-night-stand" a chance for a relationship. They have been dating for about 3 months now with 2 of them being long distance. Is there anything that RA can suggest for me to win her back? Or is there anything I ought to do? I can't stop thinking about her and I have tried dating numerous girls since then.

Summarize the given text in a few sentences.
<bot>: My clarity of affection for my ex came and now shes dating another guy. I ask for advice on winning her back or on what I ought to do.