That was quite an intro and I really like it when people take the time to really write that first post. You now have ammo to refer back after you've had a few days off the alcohol. I noticed with myself and others that after a few days we tend to forget our reasons for getting sober. You have many reasons.
Whether the drinking was caused by boredom, loneliness, the divorce, the fact that you have it so readily in your family . . . really isn't the point. The point is what are you going to do to now straighten everything out.
You say you have no place of positive reserves to draw on and I would say start with gratitude. Find gratitude in little every day things. You had a good nights sleep or you were able to at least rest your head. You aren't sick or you can walk or you have enough food to get you through the day. I mean start small and a grateful heart will build and build. That should lift your spirits.
Find a recovery program that works for you. Start with SR if you think that's going to work. If it doesn't work then find something face to face. Check with your doctor about the process of detoxing. Have someone that can check on you. Be safe no matter what you do.
Welcome to SR and just think you CAN wake up sober every day if you really want to.
Edit: Just read your second post. Mandatory that you talk about your depression to your friends, your family, SR, anyone. Don't isolate please.