Tendonitis is another possibility.
Foot infection, gout, rheumatoid arthritis are the other possibilities. It can also be ligament
injury. You may need a MRI of the foot and ankle. Meanwhile, rest your feet by keeping them elevated on a cushion or stool. Apply ice pack. Take non-steroidal anti-inflammatory such as Tylenol, Aleve or Mobic. Hope this helps. Take care!
The medical advice given should not be considered a substitute for medical care provided by a doctor who can examine you.