The problem that you have could be plantar fasciitis( swelling of the band of tissue that connects the heels to the bone). This could be due to a various reasons such as sudden weight gain, improper footwear, or even a calcaneal spur in the heel.
Next Steps
Visit a nearby Physiotherapist, and take electrotherapy such as ultrasound and ift. Even taping will help alot with the healing and pain.Stretching of the calf mucles and releasing the plantar fascia manually will give you alot of relief.
Health Tips
Do not walk barefoot , always wear a comfortable footwear even at home. You could also use hot water fermentation with EPSON salt(1 tsp).