I don't think you will fail, @utopia. You have come so far. I see you being able to go to AA meetings and perhaps get a sponsor (is that what they call your support person?) who you will be able to call when you need to talk.
And you have your Mum, who seems so supportive.
Perhaps the hospital will be able to organise some follow up care too, like a psych nurse to call you and check up on you? It would be good if you had somewhere to stay, where you weren't on your own for a few days after your hospital stay. Is there a friend you can go to?
I remember one of the worst parts of depression was the loneliness. I feel that I am fine with being alone when I'm not depressed, but it's a different story when I am feeling low.
Is ther some kind of support group in your area that you could join?