Staying after cheating
My partner (25M) is diagnosed with bipolar and borderline personality disorder. For our first year together, he was not on meds or in therapy and ended up sending a flirty text to a coworker and hiding it, though he claimed it was a “joke.” He seemed manic at the time. We broke up for almost a year and then got back together when he promised to start therapy and meds. He seemed to improve significantly for two years. Then stress recently led to a more severe manic episode (his most severe one yet) where he actually cheated. His diagnosis has since changed from BP2 to BP1, and we realized he was not being properly medicated for BP1 (on a lower dose of trileptal combined with Wellbutrin). He’d also been using weed, caffeine, and nicotine before/during the episodes even though I told him that was unsafe. He said he did it anyway because he was already manic. His therapist was also away for that month.
He now seems extremely remorseful and horrified that he cheated. He’s on better meds now and with a therapist who focuses more on mania management. My heart wants to stay, but my head is torn. Is there anyone who experienced cheating before proper diagnosis/treatment and then it never happened again? Will it always haunt me?