Fizz, welcome to the boards. I am sorry you are here. I think the best place to start is in the HW links that Cadet sent you. When I was going through my sitch, I read them over and over again, because sometimes it takes time to sink in. Also if you haven't, order a copy of the book Divorce Remedy.
Reading your intro had me thinking about a few things. We are all here because our spouse recently left us, told us they wanted D, or we found out about an A, etc. So initially we are in shock and want our S back, and that can easily be the focus. However you are bringing up some major concerns; domestic violence must be addressed, and it sounds as if she has some sort of disabling depression. Would she agree with this or does she deny it? What would she say about you in terms of DV, have you participated too? I would be nervous to even advise you with this sort of history. Has your L been able to help with these aspects? Are you going to go for full custody of your S because of it?
Perhaps in terms of posting here, the best place to start is focusing on you. You mention that you are not that man in the letter anymore. What things have changed? What steps can you take to start doing your own personal 180s and GAL? We can't all save our Ms, we absolutely cannot save our S, but we can truly become the best version of our self. Then if they don't come back, we recognize it is their loss.
Blu
“Forgiveness liberates the soul. It removes fear. That is why it is such a powerful weapon.” – Nelson Mandela