Withnail, what you're feeling is something most of us have felt, probably in differing degrees. The question "what will I do without it?".
And it is hard.
It involves making changes in your life.
But if you're seeing someone about depression, your life is obviously not ideal anyway.
I have found a great life.
Much better than the life of slavery I had at the hands of alcohol. And my mental health has improved beyond what I could have hoped.
I wish you well.