She feels if we start a family things will change on their own for him.
NO! NO! AND NO AGAIN!!!
Do not, I repeat, do NOT assume that this will change on its own. As I said before, alcoholism does not just go away "on its own." It isn't going to happen. Having a child is a joy, but it is also stressful, there's no getting around that. If your husband hasn't learned any alternative coping skills, where do you think he's going to turn for relief when the stress of being woken up by a crying baby at 2:00am every night for two weeks starts to build up?
I'm sorry. I know that's not what you want to hear, but I my conscience would not be clean if I didn't say it.
Also, I don't think anyone's suggesting that you divorce your husband or anything like that. What I, and I think others, are trying to say is it would be helpful for you to spend some time apart. My aunt went through a rough patch with her husband. He would get very angry and verbally abusive. She came and spent a couple weeks with me and my mother and then went back and, from the sounds of it, they are doing much better. Often times it is best for everyone involved, including the marriage itself. It's like I once heard a psychologist say to a couple, "You two can't live together right now if your marriage is going to have a chance at surviving."
You are expressing thoughts of suicide. You are in immense emotional pain. Pain is the body's way of telling you something's not right. Something needs to change in order for you heal. You are no good to yourself, your husband, your marriage, or your future children in the current emotional state you're in. And your emotional state isn't going to change unless something about your enviornment changes. Even if that something is adjusted and/or augmented professional help.
It really sounds to me like you are trying to minimize and excuse you husband's behaviour. You say he has mellowed out, but what happens when, as I mentioned before, the stress of having a newborn child gets thrown into the mix?
How does your husband act when he is drunk? How many times a week does he drink? Does he go out and drink with his buddies or does he drink himself to sleep at night? Does it effect his ability to function in day to day activities? How many times have you asked him to stop drinking and he does it anyway? How many times have you gotten into fights related to his drinking? These are some very hard questions you need to be asking yourself.
Personally, I don't think your marriage is beyond saving. I don't think you and your husband having children together is something that can't ever happen.
But as your situation stands right now you both need to do some serious work on yourselves and on your marriage before you can think about having a baby. Your mother in law is guilty of wishful thinking. Having a baby isn't going to fix anything.
I'm sorry if you are frustrated by what you are hearing. My original offer still stands. You can message me whenever you feel like you need to vent. I won't even respond if you don't want me to. I'll just send you smiley face or something in reply.