Looking at the history given by you and assuming that you are unable to seek medical care due to corona virus lock down I am giving my opinion.
This appears to be a case of Plantar fascitis secondary to calcaneal spur.
It is a self limiting disease but has excruciating pain in initial stage.
Next Steps
The most important thing to do is AVOID WALKING BAREFOOT. Use a soft footwear like doctors slippers or Ortho slippers. Use silicon insoles inside your other footwears.
As soon as you get up you should wear soft wears and walk on your toes for 5 to 10 min. Hot fomentation is very helpful in these cases.
Exercises which includes Stretching or massaging the plantar fascia before standing up can often reduce heel pain.
Stretch your foot by flexing it up and down 10 times before standing.
Do toe stretches to stretch the plantar fascia.
Use a towel to stretch the bottom of your foot (towel stretch).
.Placing a tennis ball on the ground and gently rolling it under foot for a few minutes can help loosen up your plantar fascia, making it much less likely to become irritated. Put enough pressure on the ball to get a deep massage. You may feel some soreness, but back off if you feel any pain.
Inspite of doing all above precautions and exercise if pain persists and if you don't have any history of
diabetes , hypertension, renal disease or allergies then you can try Tab voveran d 50 mg twice a day along with hot fomentation and Volitra gel.
You might need X-ray and Blood investigations that need to be done are CBC, RA,
CRP, Serum vit D, serum
creatinine,
liver function test.
You need to get examined by an orthopaedic surgeon and get an X-ray and blood investigations if the pain persists
Review these reports with an orthopaedic surgeon or consult me with reports directly on Practo
Health Tips
Caution to be exercised before taking medication as there are chances of acidity, nausea , vomiting, gastric irritation, constipation and allergic reaction . if this happens then please show the nearest consultant on an emergency basis.