Achilles Heel pain, spasms - OT medicos question

Achilles heel hurts like hell (throbbing) for about 15-30 seconds, then there are spasms for an equal amount of time, then it goes away. No pain when walking or jogging.

I like to rudely put my feet on the coffee table, with the left heel (the one with the problem) directly on the wooden table. If I do it now, it can generate the pain.

No calf swelling, but the bottom of the foot might have a little swelling.

Any thoughts?