Hi Talie,
I tended to swing between fairly violent hatred and optimistic love in an uncontrollable sort of way. Do the councelling for yourself, just to get your head together, and have someone who will listen to you without any strings. If he is feeling scared by your anger or alternately very guilty you being calmer will help both of you, as whatever happens you will probably want him around, even if it just for your children.
The other reason to go for the councelling is that, however hard you try, your unhappiness is probably affecting your relationship with your children. Also the councellor may have some ideas about how you can talk to your dds so that they can cope better - mine certainly did. I had 12 sessions (paid through work) and although my dh said he wouldn't go at the time, he has now asked for contact details of my councellor - I don't think that seperate councelling is that unusual tbh, I've talked to other people who said it worked well for them.
I refused to let my dh leave (always thought the first thing I would do was throw him out, but there you go you just can't tell how you are going to feel when it happens), and he coudn't really afford to go it alone. Also I'm afraid that I used blackmail, as he said he'd take the kids with him.
We have had some pretty sticky times, and I think that he has been quite depressed at times. It has helped me that I work full time, and that I have had a lot of support from work colleagues, friends and (very recently) family.
It is worth getting some legal advice, just so that you know where you stand. If his debts are in his name then he is liable (I was very worried about this as my dh ran up horrendous debts). As far as the house goes that depends on what happens to the children. If you end up going through the courts then they will make a decision based on their welfare, not an equal divide, so if you are a SAHM you should be OK.
I hope that we are building our relationship back into a marriage, but at the moment we are concentrating on being good friends. We've been together since we were teenagers (coming up 15 years now)and that's a lot to throw away. Also we still both (despite everything) love each other. Of course, that may not be enough, but I have stopped wondering if I would be better of leaving, and hoping for someone better next time!
Anyway. Sorry rambled a bit there - main message, get some support, and get some councelling. You need to get on an even keel before you can make the right decision, whatever that may be.
As I said before good luck. You will get through it!