In the past 3 or 4 days, my Betts has been squeezing himself under rocks and not coming out. He has become very slow and has to wriggle his whole body to move. He had clamped fins about a week ago. He seemed to be doing fine, until now. He IS an older betta. 4 years, probably. He also has a couple white blotches on his head. I hope this is not the end of my boy. 

? This being said the change could just have been the catalyst. Although often being described as easy fish to keep IMHO this is not entirely true. They are very tempramental fish and to care for them everything has to be just right otherwise things go wrong fairly quick.