Please Save Sebastian The Cat!

Sebastian is very sick.  He has anemia with a very low red blood cell count.  He needs a blood transfusion to stay alive, and then diagnostic tests to figure out what caused the anemia.

I have had Sebastian and his brother, Oliver, for the last 7 years--they are 14 years old.  They are very sweet, loving, adorable cats, and very precious to me.  I don't know what I would do if I lost Sebastian.  Any help you can provide will be greatly appreciated.