I know what you are saying and trust me fighting depression myself I know you are up against a tough battle. I do also admire your willingness to talk to me about this too.
I think you will have to do what is in your heart but if you have a good man fight for him.
Maybe research depression and see what others do. It is a sickness and needs to be treates as alcholism. Depressed people (men) are not weak they are sick. Do you understand. Granted he will need to want to be fixed, but he doesn't realize he is sick.
Tell him you want the marrige to work. Tell him your intentions. Then tell him you are almost ready to go if you are. I guess what I am saying is talk to him. Tell him what you told me.
-------------------- The problem isn't the game; it is that nobody knows the rules.