I'm sorry I had not met you before. Wasn't around much in March. Welcome to YT. I am so sorry for your sweet baby. Holly sounds like a dear. Please remember she feeds off of you and your attitude. I know it is difficult, but keep your head up.
 
I have been reading up on this horrid disease. Very hard. Have you considered consulting with a holistic vet? I have often found that some herbal treatments help when traditional medicine doesn't. I would find a holistic vet for a second opinion on treatment 
Have you read this? 
http://www.vin.com/proceedings/Proce...1552&O=Generic 
also, this 
http://www.vin.com/WebLink.plx?URL=h...SCWT/index.htm
apparently a big problem in soft-coated wheaton terriers -- maybe something in their research would help. 
I will add you & Holly to my prayer list. Hugs to you both