My toadstool does this every once in awhile. it will look like total crap and not open but within a week or two it starts to look good again. It may even slough off the top layer of itself. All normal.
180g Reef - 60g Rimless Reef -90G FOWLR- 125g Malawi Cichlids- 40b REEF- 34g Fresh Planted-working on- 20L FOWLR- working on
I have a mix of many different saltwater fish amongst my tanks, but I love my Tangs most of all.