See a doctor:
It could be a stress fracture (these can happen with no known trauma), arthritis, tendinitis among other things. A proper diagnosis can establish what and where the problem is, and get you started on recovery.
Sounds like the metatarsal may be still broken.
You need an xray before you keep full weight bearing.
Plantar fibromas can be made pain free by shrinking them with interlesional steroid injections.
Most common causes are:
herniated disk causing pressure on one of the nerves going to the foot (radiculopathy). Tarsal tunnel syndrome also can cause these kinds oif symptoms.
See a neurologist or an orthopedic surgeon for evaluation.
There are many possible causes of cramps.
Injury could be many things like stress fracture. Pain is not normal and should see podiatrist even if its not swollen.
Sounds extreme enough to be complex regional pain syndrome. Get checkout out by a pain management specialist.