Suggest Treatment For Bruise Under Bottom Of Feet

the bottoms of my feet really hurt, they feel bruised and I can't stand for very long, my foot doctor cant find anything wrong with them, it's been going on for about 17 years now. any advice would be really helpful. thanks, I'm 47, I take depakote for epilepsy, went through cancer twice in my 40's, now I have 2 meningiomas. I've had a partial hysterectomy and have 1 ovary left.