Tigger, do you have PEOPLE in your life? NOT your son, but FRIENDS? We all need other people. Are you going to Al-Anon? Do you have any girlfriends to hang out with? Do you have a church or other religious institution who share common beliefs?
Life (and becoming and staying UN-depressed) is dependent on BALANCE. Part of that balance is interaction with other people. When we are depressed it is VERY difficult to be around other people. But please make the effort. You will feel much better if you do.