Me too!
I have the same condition...and yeah, I gained 40 pounds too, but I did it in ONE year...ugh! Then, while trying to LOSE weight, I injured my foot on one of the damned machines at the gym. Not too long after that, my foot slipped off of the seat in the shower while shaving my legs and hit the edge really hard...then, I went to a trade show and walked for hours on the cement flooring...owwie!
Needless to say, my foot was in tremendous pain.
I did one cortisone shot...help after a few days and only worked for about a week.
I tried the splint...it sucks...I find stretching the sore foot throughout the day helps some.
Acupuncture has helped me more than the foot doctor.
BUT, the foot doc said that my preference for high heels has helped it from worsening!
Flat shoes and flip flops are the devil!
Good luck and start dressing in drag!
Marla