@JCAC16
I too had an erratic ex who threatened suicide etc. I wasted a lot of time being afraid of that. I made mistakes really because I did not know that people get worse, not better as divorce comes. Prepare when things are still relatively okay and you haven't put the papers in to the court (btw you file for divorce, you control the timetable).
First step is to talk to people you really trust - and I mean someone who won't blab to your ex.
Getting divorced is hard - you will find out who your real friends are. Its not probably the people you think right now. Touch base with all friends causally.
Get a fuck off fund. Save money. If he's a drinker then doubly important you do this.
Look at your own circumstances and can you get money or indeed borrow any money should you need to speak to a lawyer. Do it. So many women posting they can't afford it and they are in the middle of proceedings (this is not good). Yes, you may need to.
Drinking - sounds like a problem for you and your children. Do you need more support for this, ie talking to your GP as to what support you may need? My GP was unbelievably helpful - spotted and understood I had been in a controlling and abusive relationship (that might be you if you are getting suicide threats?) and directed me to sources of support.
Mortgage payments - applied to court prior to divorce for "maintenance pending suit" (not the same as child maintenance) so that the mortgage was paid. I agreed to pay half and then after resistance he agreed a sum for the mortgage and the child. Courts want children housed in divorces so this was easy to get though he did actually think he could say that he couldn't afford it he didn't have to pay it. He could afford it!
My mistakes were twofold
a) that he was going to be reasonable
b) that he was not doing these things to eff me up
I was wrong. It was unbelievably tough. I had to take everything I needed by legal force. It gave me a lot of toughness but it was worse because I thought we could be reasonable. It was not. I went to court 8 times. I won. But I could have just ignored him and have gone to court straight off and without listening to his bull shit, I would do that. I suspect lots of divorced women would say the same.
You can do it. I just took every problem I had and broke it down until I could find ways of my doing it without him or cutting him out. It worked.