I'm sorry for your losses and your suffering.
I hope that you won't give up. I hope if you stay sober and add things to your life that you enjoy, you will change your perspective on life.
Do you have activities in your life you enjoy? Do you have sober friends? Is your job fulfilling? I also wonder if you've talked to your dr about depression. It could be that a chemical imbalance is causing you to feel so sad. It might be an idea to consider medication.