Achilles tendon

I severed my Achilles tendon in 98 and spent 12 weeks in a cast pointing down and non weight baring. I have since had problems with my scarred heel when wearing certain shoes. I have numbness and can’t feel injury until it is very deep and slow to heal. I recently had such a spot when I reinjured my ankle breaking my tibia. I was put in a cast for two weeks. When following up with my doctor the ulcer had worsened and he did not recast my foot instead telling me to use crutches and wrapped with ace bandage. Should I be worried with the fracture not healing correctly? Is there anything that can be done with the numbness in my heel preventing further ulcers? The doctor said it is not a bone mass but a tendon mass and nerve injury causing this problem.