I am soo excited for you Wind. Because you've been so rock bottom you have been unable to see the point in life and seen no point in getting better.
You will slowly find as the depressive haze lifts that there are tiny sparks of light and happiness for you to discover.
At first they will be covered up and you won't be able to find them easily, but you will soon discover that by doing little acts of kindness first to yourself and then to others (however small and insignificant) will start a new chain of action which will hep guide you out of the bottomless pit you feel you've fallen into.
As I said in my first post, tiny positive steps is all you need so you don't feel overwhelmed.
Writing things down can help. You have a whole world out there waiting to be discovered. Try and find those sparks of joy, you have a lovely sense of humour so you could explore looking at life's tribulations through that lens rather than a negative one.
Perhaps ask your dh to be your companion/mentor while you try and get fit? I think keeping it lighthearted so that if you don't first succeed you don't get despondent woud be key.
I think your positives which have shown themselves clearly throughout all your posts on here Wind are your sense of humour, your intelligence, your eloquence, your fear of a bleak future and your determination.
I think your positives (plus rl and virtual help)are going to help you get you through this so that you can start seeing the point in life, the point in being alive, the point in being healthy, the point in being happy, the point in being there for your dc, the point in recreating a happy family life for you, your dh and yourself.
It's all waiting to be discovered, or even uncovered. Try looking for them now. Try planting the seeds to a happier family life, a happier you. You will reap what you sow and it is never ever too late. Consider yourself a farmer that has her autumnal fields to sow. It doesn't matter if previous seasons' harvests mounted to nothing. You can choose whatever you want to grow.... You are done and dusted with alcohol and all it did was leave you at the bottom of the barrel while promising you happiness. You know now it led to nowhere and was all a lie.
Tiny achievements mount to success. Tiny seeds mount to beautiful flowers, trees and gardens. Yes you will have storms, torrential rain, slugs and snails along the way but tending to yourself and your family with little daily kindnesses will allow the sun to start to come out for all of you x