I am sorry in advance for the crappy pics, but they illustrate my point. My betta Fluffy was doing fine up until a few days ago. He has stopped eating eating. His color has faded considerably, he spends 95% of the time lying on the bottom of the tank motionless. When he does try to swim he moves his little fins in the front very rapidly, but only makes it an inch or two off the bottom. His body is kind of curved right now. His dorsal fin is kind of clamped, but when he raises it, it does not open fully anymore. Near the tip, right on the bottom, his fin actually seems to be see through. I do not notice any visible signs of fin rot. I have also not noticed any visible signs of internal parasites. He is my 2 year old neices best friend, please help.

Here is a pic of his color right now and his overall appearance


Here is a pic of his fin up and you can kind of see the see through spot on his tail


This last pic is another shot of the way he looks now, and you can see the spot on his tail better

Change the water and give him some Maracyn. It seems to help fish that act like that...

Hmm.
It sounds like internal infection or parasites.
You could try Maracyn 2 - for the internal infection, and that's also good for treating under-the-weather fish that won't eat.

And do give him a water change too :)