Even if you are not sure what you want to do, like people have said you can consult a lawyer for free. That's what I did just to see what my options were and what I would be facing. The lawyer I consulted is very good and was straight up...he said he has seen alcohol destroy many marriages and you need to protect yourself. To give you an idea he charges $300/hour and a $2500 retainer. A little pricey, but in line with my area. Also if you can work out an agreement with your spouse it will cost a lot less. Just FYI.
You are facing a lot right now and I would not make any huge decisions in the heat of the moment. I thought about things a long time before I made any decisions. Just remember the most important thing is protecting yourself and your kids.