Hi OP I’ve just read the thread, what an awful situation with your mum. In regards to your relationship it seems to me that you are probably existing in a constant state of adrenal overload, your fight or flight response is stuck in freeze mode.
It is profoundly unhealthy to live in such a toxic relationship, it sounds like you can never relax, never stop being attentive to his moods, needs and pettiness.
The only area you have agency over is yourself and your choices, you could bend yourself into a pretzel and he would complain it wasn’t the right shape, someone else could do it better etc etc
Constant dripping tap of disappointment and negativity.
Your dc and mum have very limited time in which to see each other (and they haven’t for a year) until your mum deteriorates and is no longer able to recognise them and may display behaviours that they find upsetting. If you miss the window of opportunity for this it will be devastating for you and them.
Read back through this thread and you will see that this is like a hamster wheel - You are constantly cycling through different emotional states and they are all directly related to him and how he is feeling/behaving. You have no emotional energy left for yourself or your dc.
It’s easy to sit here and say leave, it’s incredibly hard to do it in real life. But you can do it if you choose to, you can choose to take control of your life and create a happier, peaceful one of your own making. I did and went from someone on top dose AD’s and therapy to medication free and much happier. Ultimately it’s your choice, my dd is far far happier in a home without tension and arguments and I am a better parent.
One last thing, in your post you said ‘we have to get jobs’, does that mean you have lost your new job?