Hello Hotpink, and a warm welcome.
You and your 18 month old daughter are your prime concern, so safety is very important.
I used to run hotels and people who couldn't handle the alcohol were discouraged from not drinking, I'm not saying that this should happen to your partner, because it's only up to the person to make that decision, otherwise it won't work.
When a person leaves a relationship due to various circumstances, promises are made that everything will improve and not happen again, unfortunately, it does on many occasions, making it awkward and not safe.
You deserve someone who thinks you’re wonderful, loves and respects you because no one can possibly be perfect and if they do, then something isn't right.
If you separate, that doesn't mean the love you have for him will stop, you can love someone and not be with them, and I can't tell you what to do but can suggest that this isn't the scenario for both you and your daughter to develop.
I'd really like to hear back from you so this can continue and with other people joining in.