You know you don't have to stop loving her, you just have to move forward. If you quit associating the two then you will see the future. I know that sounds complicated but here is the long version:
Just because you fall in love with someone and marry them, and it doesn't work out, doesnt mean you have to stop loving them. As we all know there are different forms of love and you should always keep as much love in you as you can (it helps with depresion). Moving forward in your life, be it alone or with someone else is not a bad thing (moving forward and seeing a progression of you life will also help minimize your depression).
The best thing anyone an do for themselves is grab a pen and a piece of paper, make two colums, one for GOOD and one for BAD. Fill the colums with the things in your life that are good and bad, include everything. Then walk away. When you think things are so awful look at that list and see what can be moved to the opposite colum and you will see that sometimes the things we get depressed over are the mole hills that we have made into mountains.
Everyone is depressed in some way. It's how you see your life and how you approach the problems. You all might be saying , yeah its easy for her to say, but the reality is we are all screwed up. My son died 10 months ago, and he was only 19. This was my only son, and all i have left is my daughter. I lost 5 months of my life because of his death and my depression. One day I woke up and looked at myself in the mirror and thought " what in the heck am I doing?" I have my daughter (GOOD) my husband (GOOD -even though he is my second husband) my house (GOOD) the rest of my family (GOOD) and the list went on and on and on. Then I looked at the BAD and I saw, my son's death, but the GOOD part is at least I had 19 years with him, at least I know what he did for those 19 years and then all the GOOD he did in that short 19 years. Oh My GOD!!! I have to move forward...and I did, I got a new job, I fought the depression and made an effort to make GOOD and ignore BAD.
The key, as hard as it is and as much as we dont want to, we have to MAKE AN EFFORT.....
Nate, what you are feeling is NORMAL, but dont stop living, dont stop being yourself, its OK to move forward and its ok to be happy and its OK to remember all the great/fun times you had with your ex, but MOVE FORWARD, its only one step at a time.