Most likely, you have severe Achilles inflammation as shown below. You should do leg stretching exercises 3 times a day for 15-30 seconds each time. Of course, if the pain does not decrease after 15 days, it is better to see a doctor.
Image of leg stretching exercise. Stretch until a little pain occurs in the leg. The back leg is straight and the front leg is slightly bent. Lean your hands on the wall or anywhere.