I think it may be a good idea to speak to womans aid, your gp, ss and hv, log this situation so that you have a 'paper trail'.
It could be seen as a child protection issue and you may be able to get advise on how to deal with him.
If you seperate it is possible to insist that in order for you husband to have unsupervised access then he needs to show that he is clean alcohol wise by having a hair strand test (to show level of alcohol consumption) and a liver function blood test. If these tests show above moderate alcohol consumption then he can be asked to have rehab. This would have to go through the family court and have a judges ruling.
Is there any dv between you and your dh? If so you may qualify to get legal aid. It would defiantly be a good idea to talk to a solicitor, many can give half an hour free so ring around.
If there is dv within your relationship you can log it with the none emergancy police 101, this will also help with a paper trail and helps to access free legal aid.
Speak to people and ask for their help.
I hope that you have rl help from family and friends.
Alcoholism is a very 'selfish' addiction, you may find it useful to read some books on it, also join help groups for families that are effected by this issue.