If you are "focusing" on getting hurt and leaving your kids with a "handicapped" or dead mother, than some cognitive behavior therapy might help. You shouldn't let this incapacitate you. Yes, be aware of the risks, learn to ride assertively and safely, and realize, yes you could get hurt, but don't let it stop you from enjoying something you like. Anxiety where you picture a bad thing happening is not something you need to live with.
Mountain biking is kind of in another category because crashing is just part of it. I only stopped because of my osteoporosis... I didn't mind crashing, as it's part of the experience, but I couldn't risk it. I didn't attempt things beyond my ability and when I actually spent some time practicing, I did improve. I went alone a couple of times, on my way home from work. I got lost, but I survived.
I do a lot of things I swore I would never do, and I am pretty proud of it. I come from a family of neurotic worriers, who are afraid of everything. It's no way to live your life.