I think you need to confront your personal demons and come out the other side confident in yourself. If he (and you for that matter) are still single then there is nothing stopping you getting to know each other again afresh.
I know you love him and it's hard but you can't place your happiness on this man and your relationship with him because if it were to end, you will crumble. I know this because I did this in my darkest days and I crumbled. I promise, I am not being cruel, you need to know that you need to be independent and can do it.
Because I don't know what the trigger for your depression is, I can't advise a way out of it but sometimes, if you come outside of your shell and stop thinking about your problems, they will not seem so bad. Once you can start focusing on how lucky you are (possibly do charity work so you can feel achievement in helping others) you can concentrate on consciously changing your life for the better. Taking control feels so good, even if it is just a new hair style.
I really hope this guy sees the effort you make and you get what you need, not necessarily what you want. Good luck.