I had this problem a few years ago, you have all my sympathy, it took about 18th months to get rid, it went gradually. I used to use a towel to stretch my feet, by wrapping it round my toes and pulling upwards whilst sat on the bed every morning and evening, also standing up and my toes and if you understand this, its hard to explain, walking across the floor pulling my self with my toes, all exercises given to me by my podiatrist, I also had orthotics which helped and I still use them sometimes, but it is very painful, good luck. PS. Trainers were prescribed also.