Erythromelalgia often responds to magnesium. Magnesium is also used in bone mineralization.

What I think happens is that the membrane over the bone has been damaged. If there are fragments moving around, without the protective membrane on them anymore, then the body forms a localized tissue reaction. Crushing type injuries are pretty damaging to all the tissues in the foot. So it might not be just the bones themselves, but a combination of tissues reacting.

The menthol in the the Salonpas patches should take down any heat or burning type pain for you.

There is another menthol containing product called Biofreeze gel.
This works well for burning too. But using the Salonpas you should not need the Biofreeze on top of that.

If your redness changes, starts spreading or including the whole foot, that is the time to start worrying. Also you might seek another opinion.
Foot injuries take time to get better. And sometimes they do not return you to what you were before... there may always be some issue with that toe. (stiff, color changes, etc).