Dedicated riders will prety well always get back in the saddle whatever. So I hae no fear for you there. But too much or wrong pressure from the stirrups does make some feet hurt, with or without stress fractures and operations. I found special inner soles helped alot to improve the area under metatarsals. My chiropodist is a rider and could explain and advise the person who made them accordingly. I'm not sure if it's an answer for you but I started using Ariat boots that have a stiff plate in to reduce strain for longdistance riders, they don't give way when you are out of the saddle. Or not until they are old. I always use special inner soles in them and in winter thick socks and the feet are happy. I have no problems working and walking around the stables. In elegant boots in summer I still have the inner support but maybe not enough padding. I think expertise in orthotic production plus careful search for the right riding boots will help. What might be a problem is being 55! My female riding friends who also spent alot of time in the saddle and are 50 plus all seem to have aches and pains...and more so when we ride young fit horses, but we aint giving up yet! Have fun!