Hey I had this done TWICE. Not as much as you it sounds like.
I really don’t recall the nutrition at all - I know I was riding/racing a lot at that time in my life. If you are using cadaver skin/tissue its one problem. If you are taking your own tissue this is going to hurt and be harder.
The graft for me was covered with silly puddy for a few weeks - that meant I could eat almost anything just used half the mouth and smaller pieces going in.
I do recall why the first one didn’t take, and that was from too aggressively brushing and using it once the puddy came off. So be careful opening bottles with your teeth.