HI ukh
I'm in the UK too.
tbh this sounds less like his alcoholism and more just the way he is.From a woman's perspective I've been there and my only advice will be back off. Don't ask him outright, don't chase him and try and decide what YOU want. You can't and wont change him and if he isn't giving you what you want in a relationship then you can't make him give you more or be more available affectionate etc.
What you can do is decide what YOU want and what you are prepared to put up with. You say you have been intimate once. I hate to say it but some men do lose interest once they have 'caught' us. yes I know it's old fashioned but it happens. I've been there and it's not unusual for a man to back off.
In my experience if a man hasn't been in touch it's because he doesn't want to. When he did call and I was so available it's just easy for him. I wouldn't even ask him outright - you decide what you want to do and don't let him dictate all the terms. don't respond to his messages, don't be so available. Maybe he likes the chase. Then again do you want to be with a man who likes playing games?