I agree with everything oldfishlady said, put him in his own tank (QT = Quarentine) Do daily water changes to prevent infection, as well as some aquarium salt, and some quick cure if you can find it (I swear by that stuff)
High protein foods such as Bloodworms are a good idea, make sure the water is warm!
IAL means Indian Almost Leaves
http://www.indianalmondleaves.com/
Edit to add: If you are looking for good small pellets that are great for smaller bettas and are high quality look for Hikari Betta Bio-gold pellets, or Topfin color enhancing pellets!