I have found two solutions to this. Although I must admit they apply more to parkflyers than nitro planes. First have a plane that even if you do care about it, you know it can survive anything but a major crash, this might be a bit tougher in the case of nitro planes, but oh well. Second, I have actually found I enjoy flying my 3d plane more than the others just because I know that whatever happens to it, other than catastrophic failure of some part, I can save it. Sure, the landing is nerveracking for me, but the flying is a joy. Or just try the classic back to basics approach, just do the relaxing things first than go back up, and if its just not your thing to always worry about your plane, just fly things you are confident with. If you aren't enjoying flying because of the risk you may want to reconsider what you are doing it for. I know I have a couple times after one of my planes took some damage, but I'm always back out there.