Post-Surgical Heel Blistering

I ruptured my achilles tendon and had it surgically repaired.
Barefoot all is well however wearing shoes is painful.
I know have a “bump” of scar tissue on the back of my heel/ankle area.
Anytime I wear shoes with backs its painful and it blisters.
I have been using a Tulli lift in the upside down position which relieves the pain longer but eventually I blister.
Any ideas???