Welcome to the board. You will find that many people here are in the same situation as yours.
I am not a vet, but have been making enough mistakes that finally it all makes more sense to me now.
First, when anyone says to you that it will get better with time, it is really true. It seems for you right now that in your sitch, it will hurt forever... Yes, it will hurt always but not the same way all the time.
With time, you will know how to prioritize your needs, thinking about him won't be the same pain anymore. It will hurt, but in a different way.
The more you improve yourself and look for things to do for yourself, the easier it will get.
It's not a piece of cake when you have kids to take care off. But, as much as it is hard, we can stress enough that you need to find something to do and get yourself busy.
Look at everything...your hair, the way you dress, your weight...start small and look for other stuff too. Go out with friends, even if it is for a cup of coffee.
The crying, depression and anxiety gets better too. That's why everyone will say you need GAL activities. It helps with the anxiety and depression. You are relearning to be you again, it's very hard and will take time, but at the end it is the one thing that will help you to get him back, if ever.
It all seems to be mixed up right now. Try also to understand that your H is also very mixed up. At least he is not ignoring his kids and is helping you around the house.
Calm, be patient, it takes time to adapt to the new life you have. Take good care of yourself and as hard as it may sound, you need to eat and sleep well.
The journey can be a long one. So, have that in your mind that it will take longer then two or three months, this will help you not to think everything needs to be resolved over night.
You can do girl. Believe me, things will ge better, and I can say that time to time it will get really hard to deal with.
Hang in there and keep posting. You will feel much better tomorrow/
