I am wondering if perhaps you might have gout. You do need to check with a doctor for a proper diagnosis… they have developed new meds that are doing a lot more for gout than they had years ago…which is a good thing.
I am just ‘guessing’ that this could be what you have because I have a friend whose gout started in this manner. If you have diabetes do not waste a MINUTE and get yourself right to the dr…very important.
Best wishes to you and let me know what the dr has to say. Take care.