Hi Fubar
I recognized your name and looked back at your first post to refresh my memory of what was going on.
My first question is are you seeking any professional help for the PTSD and depression? If you are not then it's no wonder you're losing. You need to do what you can to seek professional help. And if you're having addiction problems, then all the more reason you need professional help.
If you are going to try and do it alone, then you will fail. These are all issues that you need help, accountability, counseling, treatment and, possibly, some medication to help you work through. And, yes, God can do it Himself, but often times He prefers us to work through our issues instead of just deliver us.
As far as your past, this is you holding on to what God has already forgiven. The issue isn't God struggling, it's you struggling. God's forgiveness is absolute. He knew His forgiveness would come when He allowed Jesus to pay for you sins on the cross. God was not caught off guard by your sins. He was thinking about them all on the cross. And yet He still died for your sins. The very sins you are holding on to and letting shame control you.