My dad had PD and suffered a lot from foot pain. In fact that is really the only pain he complained often about. He did have a podiatrist make up orthotics for his shoes and that helped him tremendously. It seems that in one foot his toes would curl under and with the orthotic, it helped to prevent that. He also went for physical therapy on and off when Medicare would pay for it and that seemed to help as well. His podiatrist picked out appropriate shoes for him which also did help.
I suggest you see a good podiatrist to see how he/she can help you. Just a suggestion & I hope your foot feels better soon.