Hi Ulysses,
I'm having a rough few days and I'm looking to sort things out in my head and get any support I can find. I wonder if this post is too long?
some questions are easy to answer: Yes, the post is too long for a post that typically elicits a lot of responses. No, the post is not too long, you have to write what you have to write some times and even if it is just for yourself and nobody can tell you otherwise!
My family and friends and I think my therapist feel I need to divorce my spouse.
This is a recurring theme in your posts. You are feeling under great pressure from that side. Families have their way of looking out for the best for you - whatever they consider it to be. Same goes for therapists although the latter usually tend to throw decision making back at us. What makes me wonder a bit that you feel so much under pressure from that angle.
You wrote that your H is a sex addict but then on the other hand it also looks like you had a longer marriage without affairs. Also he started another relationship and was not sleeping randomly around. While there may have been unusual sexual aspect to that affair it does not sound like sex addiction. Borderline can take many, many faces. A lot is driven by fear of invalidation and need for validation.
PwBPD often form very deep and long lasting bonds and struggle to detach. You see it right now with OW but the attachment he has with you will be stronger considering the duration and children. This does unfortunately not prevent him from acting irrational and self destructive. Involvement of his parents in his affair is most unusual and calls into question his as much as their common sense.
He seems to act up, too, when I've got positive things happening in my life and am getting stronger. My therapist has told me he destabilizes me but I'm just now seeing it and believing it.
Of course he feels threatened and invalidated when you change. It would be natural to feel also fear of being abandoned considering all what has happened. These times of change are hard on pwBPD. Being aware and using plenty of validation of these emotions can help to bridge the time until the new normal is established.
He said he had personal issues affecting our marriage and wanted to work on himself. If I asked how it was going he sometimes would tell me I was controlling his therapy, so I stopped.
So he is in individual therapy? That is an important factor in bringing about change. Although it tends to take a while to take hold and the first months are often accompanied by even more confused behavior. In that sense it can get a bit worse for a while and it is important not to get baited into his mental chaos until it is sorted out. Discussing and finding agreements with him in this state is a bit a futile effort that may add more to the overall distress than it is worth it. Focusing on yourself, boundaries and validation may be the best for a few months.
You are pushing on a lot of fronts for change and you are feeling exhausted. Maybe Ulysses was wise that for a short while he restricted his options, got himself tied to a mast and simply did listen?