Dearest nsox,
You will probably get some heated responses from people who have had to live under these conditions. I have and will tell you children see and feel everything.
Marriage is sacred but when you or your children are in danger, it is time to leave.
Consider this, if your H gets caught drinking and driving with children, your children may be taken out of your custody (family home).
You are not TRAPPED, you are feeling trapped but you have options and choices.
You can take your personal power back. You said if it were not for the children, You would find some way out, well, for your children find that strength.
Embrace all the resources available to you. Here on pc you will find people who have survived this. You/children are worthy of a Happy life.
Husband had issues prior to you, these he will have to work on with professional help.
You can not fix him or heal him, you can support him by giving him space and time.
You cant trust an active addict.

Your kids can deal with the truth no matter how bad it is.
If you make excuses, downplay irresponsible behavior, you are showing them its okay and this will be very harmful, I hope you seek out and accept the help that is here.
You can show your children how to be powerful Mommy is!
Hugs and Prayers
Happiedasiy.