I'd start with a good podiatrist. Did you stub it? Or drop something on it? How do you know it is broken? Did you have it Xrayed?

If you did all that, then finding a new RSD/pain person makes sense. But if you did not get it xrayed, you should. Some stubs shove the bone into the metatarsal joint, and if not fixed quickly, can ruin your foot, as it heals wrongly. This happened to my neighbor while she was vacuuming...it turned into a huge mess for her, from an apparent simple injury that wasn't simple.

I was working on a rock wall a few years ago, and a huge boulder rolled out unexpectedly onto my foot...broke my big toe in
2 places. I went to a podiatrist the next day, and he gave me a special shoe to wear. It turned black and blue too.

OMG. I hope your former doctor will still be able to help you. I agree with mrsD, how are you *so* sure you broke it? Has it been x-rayed yet?

Let us know what happens.