I'm currently in my second marriage. The first time I was married to my high school sweetheart. We were together for 7 years. They cheated, then I cheated and vice versa, and it was a never ending circle of lies and infidelity. I was very self destructive for a while during and after the marriage. Constantly having sex with people I shouldn't be, drinking 24/7 and self harming. We got divorced and 6 months later I met my current spouse. 

They were wonderful. Helped me learn about myself and who I was, pushed my boundaries on accepting help with my mental health and encouraged me to become a better person overall. When I met them they had were sober so I hopped on the train too. I got diagnosed with BPD about 4 months in to the relationship and they were very supportive. We had/have the usual ups and downs that relationships have. But it is/was the healthiest relationship that I've ever been in. We got married after 8 months of being married for other medical reasons and have now been married for 20 months. 

I've had great luck with finding the right medication for me, but underneath it all I can never stop worrying about them cheating on me. I knew that if they ever did/wanted to cheat they would talk to me first and we would figure it out. Over the last few months I really thought that I was over all of the worrying because we had worked through so much and they never did anything to hurt me on the grand scale. 

They were in military training from Sept-May. During the training we didn't communicate a lot but we were making our way through it. They started drinking again and ended up making out with someone else, (while it isn't a big deal to some it's just as bad as sex for me). And the worst part was I had to find out over a week later from one of their friends. Once they moved home early May they were still treating me like trash. Making their friends a priority over me, not taking responsibility for their actions, etc. 

It's been a little bit over a month since I found out and I can't figure out what the right decision is. They put our relationship in jeopardy and didn't think twice about it, but can they change back to who they were?