Bloody hell! That’s so nasty.
I’d take it a step at a time. For the next few months, focus on your treatment and recovery. Likely to be best for you to stay living with your DH, if you can bear it, so you don’t have to worry about working and it’s easier to juggle childcare. But, if you feel your marriage can’t be saved, even if your DH works really hard on biting his tongue, then start to plan a future on your own.
Think about the best job options and roughly how much you may be able to earn. Start to figure out how much you’ll have if assets are split and what housing options that might give you. How much of a mortgage you may be able to get. There’s a lot to research and inquire about. Could be something to fill your time with during treatment, at times you feel up to it.
If at all possible, it’s best not to end a marriage in a rush. And to ensure the split is as amicable as possible, so it’s easier to co-parent. You’ll have to think about the impact on your DC of your treatment, followed by the separation of their parents. However much you cushion them from any anxiety and stress, both will still have a big effect. If he’s verbally abusive to them, start to log evidence, so you can argue for full custody.
Then, during your recovery, start to rebuild your circle of friends. I guess a positive is that having treatment for cancer gives you a reason to get back in touch with people. You can say it’s made you reevaluate the people who enrich your life and you’d like to see them more often. Might be a bit less awkward than if you contacted people out of the blue.
I hope the treatment goes as well as possible and you’ll then be able to turn the page and start a new chapter of your life where you’re free of verbal abuse. In the meantime, every time he says anything vicious, walk away and remind yourself it’s his problem he can’t regulate his behaviour and be determined not to let it affect you. Hold your head high.
Good luck with it all.