My experience with isolation is different to, methinks. For the seven years of my relationship with my sufferer, I didn't know he had PTSD (it's becoming more apparent that HE knew, even if it wasn't formally diagnosed, and didn't tell me - so there's that). So I didn't know what his attempts at isolating were, and to be fair, he didn't usually need to isolate from ME necessarily. I was within his "safe zone," so my being at home was generally ok, even if I would just leave him alone.
It wasn't until he was triggered by something I did that I became unsafe, so his need to isolate turned into a need to run as well.
And, because he hasn't done much research into PTSD, and isn't being treated, he doesn't really know or accept that the isolation, running, loss of feelings, or even being triggered as being a symptom of the ILLNESS and not necessarily an indicator of ACTUAL danger. So, for him, the need to isolate and run, and the loss of feelings towards me, are all indicative that the relationship needs to be over, period, and not that his illness is taking over.
Meanwhile, his push/pull happens because we still live together, we still get along really well when he's not directly triggered, we still joke and laugh, and we still share meals and go out together. I try to just do my thing and leave him alone, and he seeks me out, sends messages throughout the day, and sometimes even acts as if nothing is wrong. It's crazy making.
I would be happy to readjust our relationship to its new "normal" - give him his space when he needs it, be there for him, still call him my husband, and readjust my own expectations. But even trying to have that conversation makes him disassociate - the last time we had, what I thought, was a rational, beneficial, productive conversation, where we were both present and practicing active listening, it was like we had totally different conversations (we had agreed to put "splitting up" on hold, just "be" for awhile, and see what happens). He later claimed, at our last couples counseling session(where we talked about it again), that he "never said any such thing, hadn't changed his mind, it's over," and I wonder if the session made him disassociate...we'll never know because he won't deal with his PTSD.
So anyway my rambling point is (or points are...), as
@Snowflakes said recently, and we (mostly) all eventually realize, there is nothing we, as supporters, can do to help our sufferers, or even stay IN a relationship, unless THEY want it.
You know you cannot change him. Love is powerful but your love cannot change him. He must change himself. You can support him emotionally but you cannot change him.
Sometimes, love isn't enough, and sometimes we need to love ourselves enough to know when to walk away (or allow their push to actually keep going). My own therapist would also agree with
@Snowflakes - the sufferer has to do their part, too (she actually said, if, once we are living apart, if he wants me in his life, he should have to show me he does). And you're right,
@Linzee, he also has to let you back in enough to show him you're there. Until he does, take him at his word, that he needs to be alone.