I've had two stress fractures on my tibia. Had to be put in a cast to resolve them.
I thought I had a stress fracture in my foot, but it turned out to be a neuroma, which required surgery. Actually, it required two surgeries.
I also had plantar fasciitis. That was pretty painful, very annoying, and resisted all treatment.
Each one of these injuries felt different. The neuroma and stress fracture feel somewhat similar, but PF felt different. A good doctor should be able to diagnose your problem. Probably the best indicator for a stress fracture is that if it pressed, it will hurt. Stress fractures don't always show up on x-rays. A bone scan, where they inject a radioactive tracer in your blood, should show a stress fracture (the stress fractures on my tibia were glowing so much that the tech looked at the image and said "wow - that's bright - that must hurt"). If it is a stress fracture, about the only way to resolve it is by staying off it. I had a hard cast for my stress fractures, but now they would probably use one of those hard plastic boots that look sort of like a ski boot. Usual caveat: I'm a doctor, but not a medical doctor.