When you make your decision to leave it must be final. You must be at peace that you have done everything you can to save your marriage and it is now over. You are not going back.
If you don't have a permanent full time job with health benefits from which you can support yourself - don't leave. That job needs to be in place before you exit. If your husband doesn't have a job or inadequate income, you may get hit with having to pay him maintanence.
If your name is one the deed to the house and the mortgage - DO NOT MOVE OUT. You need to stay in control of that asset as much as you can.
Take your name off all joint credit cards and/or pay them off before you file for divorce. You will not be excused from any debt with the credit card company, mortgage, etc just because the Judge orders it is your spouses debt. Your lawyer can explain that one and it's no joke.
After filing for a divorce, file a motion to freeze all the retirement accounts. If your spouse liquidates the accounts, the Judge may order he has to pay X back to you but in the real world you'll never see that money again.
The family court system is the most immoral and abusive institution on the planet. Whatever abuse you put up with out of your addict spouse may at times seem minuet in comparision to the crap the legal system will put you through. The Court will not give a crap that your husband is an alcoholic, etc. They are there simply to grant you a divorce. You won't get what's fair. You can take the same case to three different judges and get three different outcomes. The only thing that will be the same is that you will get a divorce decree.
Your lawyer is not your friend. Read that again. They make a killing off of a fight (of the illusion of a threat) not agreement.
Your children are not your counselor, legal advisor, financial planner or friend - so don't go there. Focus on being on being a mother to your adult children and be honest with them but know your boundaries.