Help - My Fiance is depressed

Hi.

My fiance is 29 an has suddenly started going off the rails. He's decided he wants to go on holidays by himself, loves living alone and wants to start drinking again (he's an alcoholic and quit 6 months ago as he was drinking himself into an early grave).

We are a great couple and the best of friends and he says he doesn't want us to split up and I shouldn't worry about that he's just really miserable.

I know he suffers from depression and comes from a family where his dad is a manic depressive.

I've sat and talked to him and we got some herbal remedy tablets for him to help lift his mood but he says he doesn't want to spend the rest of his life miserable and taking medication to give him a bit of a high moment.

What he doesnt realise is that the alternative is drinking for the rest of his life instead.

As most people do, he thinks the grass is greener on the other side and remembers his life before being with me and being easy and fun but he seems to forget that he was a lonely, miserable alcoholic when i met him and he got with me because of those reasons.

He says I'm the woman he wants to spend his life with.

I know that when men get depressed they externalise and blame the people closest to him but Im not sure what to do.

Please help.