Foot issues

I've had two surgeries on my left foot and the second one required removal of muscles, nerve endings, and bone. I started to train for boxing after i had supposedly recovered from the second one. The first thing my trainer had me do was get some footwork down. In the beggining it was rough because i had had horrible balance up to that point my entire life but after some work i started to get pretty quick on my feet. My doctor told me there was scar tissue in my foot that would break up and would result in some pain.

After awhile i got this sharp pain in my foot (now mind you my right foot is wired much differently than my left because of the removed muscle i had to strengthen other muscles in my foot to over compensate so it doesn't bend exactly how it should) and now apparently i have a stress fracture thats not going to heal. The pain pops up after i've been standing upright or walking for awhile and i can tune it out but when i try to get up on my tip toes it's not happening. I can ignore the pain to a degree but after awhile its gets extremely rough to stay on my foot like that. So at this point i don't think i'll be able to get the normal tip toe stances of a regular boxer. So i'm thinking that maybe i can compensate for my foot speed by being able to move my upper body quickly out of the way of punches. Now i will in all likley hood be fighting in the superheavy division as an amateur (a division not known for great footwork) and im wondering if i can get away with a flat footed stance or do you think it will catch up to me?