What happens to my cheese when I overcook it
It's overcooked. Maybe not burnt, but it will be grainy, crunchy, or rubbery. Depending on the cheese. I've never eaten that kind of cheese, but you can still eat it, probably, but you probably won't like it. 

What happened is you basically bubbled all the moisture out of it and you're left with the fat and protein clumps that are usually uniformly dispersed throughout the cheese.