Will my wound still close if it is this big? Do i need a skin graft? 3 weeks post TT. (photos)

3 weeks post op tummy tuck.i got wound separation and necrosis. I feel so terrible.my PS keeps telling me it will close on its own, but this is the biggest wound i have seen in this forum.I only do wound dressings. It gets worse everyday. Do i need a skin graft because it is too big? I go to her clinic 4x a week and do hyperbaric. She said it is good for wounds but it is getting worse. Can you please give me your opinions.i'm begging you. Thank you