My girlfriend has BPD

Hello everyone, glad I could find this group.

I recently found out that my girlfriend had cheated on me. We are a lesbian couple and have been very happy and in love for 2 years.

She started a new medication for bpd, went away for 6 weeks for a new job and she changed so much. Her personality changed and she didn’t believe anyone. She started to talk to a man at her course and I saw it as flirting but she didn’t. She removed him from her messages and said she didn’t talk to him again. She came home to me every weekend and nothing between us changed. She would still act totally in love with me and talk about our future. On the last Sunday she was home, she went back to her course for 3 days. On the sunday night she got back to her hotel and instantly went out with him. The next 3 days she was having sex with him once and twice a day. In this time she was still messaging me saying she missed me and wished i was with her. She would make up stories that she feel asleep when in reality she was having sex with him. She would send me photos of what she was doing and he would be with her. It’s almost as if she recreated what we had, our first date, wearing his clothes to bed, getting dinner, watching movies. She would message him while laying in bed with me. On the day of her graduation he had slept over that night and they were together in the morning. She messaged me like she would any other morning. I tried calling her to wish her good luck and she said she couldn’t answer because she was getting ready but it was because they were having sex. Then she called me right after like nothing had happened and me be so proud and encouraging to her. She would constantly lie and tell me he wasn’t there and she wasn’t anywhere near him but they would sit together at every event.

When she came home for her course i questioned her about cheating on me because i knew something wasn’t right. She told me i was making things up and i was being toxic. She continued this for 2 weeks while messaging him everyday while she was at work and hiding it when she got home. She never told me, i found out and she hasn’t been able to tell a straight story since. After i found out she called him because she needed someone to talk to. She then attempted to end her life and is now in a psych ward. I can’t help but tell myself it was her impulsive and self destructive behaviour that caused her to hurt me. I also can’t understand the betrayal and the two lives she was living while acting completely normal with me.

She is finally getting the help she needs but I don’t think it should have taken this for her to get help after I begged for 2 years.

She says she’s disgusted by what she did and it was like someone else was making the decision for her. She’s always been disgusted in men and has cut people off for lying and cheating on their partners. But now she says she enjoyed sex with him and doesn’t know why. She says she regrets what she has done and has lost the best thing that happened to her, but is that just cheaters talk?

Her going to the psych ward is a huge step, she was never even interested in counselling and refused help.

I know that this behaviour wasn’t her, she would never be capable of hurting a fly but in those 3 days something switched in her and she was capable of such a thing.