How certain are you re diagnosis?
Thankfully I barely recognise how miserable I was when I wrote my prior message. I get the odd twinge but now much improved doesn’t affect my riding
Bit of rest initially
Orthotics with arch support and medial heel wedge in cycling shoes AND I wear them full time now in all shoes
Static holds on the tiptoes of the affected leg for 30-90s, adding weight if required with dumbbells (I did this in preference to active heel lifts or eccentrics)
Keep on riding but not during rest phase and not if it is triggering it
Hang in there