Snow sounds very much like DH has some demons he really has to tackle. You can't fill your own cup if DH keeps randomly poking a hole in the bottom of your draining it. It must make you feel on edge waiting for shoe to drop.
I wonder if it's about of sight out of mind problem. He puts DSC in a box and mentally takes it out again when he's here. But the box is more like Pandora's box than a nice Christmas box ?
It's clear you love him, it's also clear you have been running a marathon for a long time and that has effected the level of what you would accept vs what you accept with DH because you see his pain. Your levels may not have fully returned to the level of what they should be. Even if you feel your tank is much fuller so to speak.
Like having a glass of water when out in the desert and thinking omg I feel so much better but actually you maybe v dehydrated. I really do hope you get the outcome that makes you happy. You deserve to be happy.
I hope your DH can do this for you. But I want you to know if he can't, it is definitely not your fault, and it maybe just also not his fault. Sometimes even the most perfect fit missing that last 0.00001% cm make a situation not fit. I'm not saying this to be unkind, I'm saying it as someone who has had to walk away from a similar situation and it broke me.
Re practical advice look towards the future, just you for the moment what does it look like, what dreams have you got, what adventures do you want to take.
The gift of fear is a good book. I recommend it for some of the work I do with a NFP. It's about listening to your instincts the ones you silence and the reason why you silence them, various chapters that won't apply to you but interesting never the less.
Just a gentle suggestion to say any perm decisions, you take try not to do it over festive period. The festivities tend to be very much geared towards families and togetherness, but what isn't advertised is the fact there's a higher rate of GBH in families. My best friend is a nurse and she says the amount of people coming in with knife, fork wounds over Christmas by family is alarmingly high.
Be kind to yourself please.