Gaping hole where my belly button was. How long will it take to heal with wound vac? Seroma healing time? (photos)

I had a TT three weeks ago in addition to an umbilical hernia repair. The hernia was around the umbilicus. the skin sloughed off and I now have a wound there. It's packed at the moment. Wound vac is on its way. The problem is, while laying down, as I would have been on an operating table , the umbilicus lines up with the new hole. However, when I stand up, the umbilicus goes above the hole. Will this heal? . Do these things happen often? How long, with a vac, can I expect to be healed?