When I head to the field for a day of flying I certainly don't intend on crashing... However, (I don't keep a trash bag in the plane), I do know that there is a possibility of damage or even destruction of any plane on any day.
I suppose it's easier to lose an airframe that you only have a couple of hundred dollars and a few hours of time into, compared to a labor of love with hundreds of hours and who knows how much invested.
As for overcoming depression, I guess it's all about the frame of mind you have while enjoying the challenge of the hobby. I get pretty aggravated when I do something stupid that caused the crash, but hey, as was said before, learn from your mistakes and keep moving forward. You will have an opportunity to reinforce/repair your plane or even get a nice shiny new one, plus you have a great story to tell of what a great bird she was and how she went in!
What goes up, must come down whether its upright on it's wheels or augerd in out in the north forty...
It is definitely a bummer to lose a plane, but the adrenaline rush of a maiden flight or the satisfaction of a perfect landing sure do outweigh the feelings of loosing one!
Keep your chin up, and FLY ON!