Sorry to read this about your dog. Agree with Ghilly. I assume you can't afford the Vet right now? If this has been going on for two years, maybe you could have tried to put some money aside here and there. Not being judgemental but I used to keep a separate dog account that I would put a few extra bucks into when I had it.
Hope you can find some resolution.
Cocker spaniels are genetically prone to autoimmune problems that can result in skin issues and loss of hair. The only way to be sure of what it is so that the appropriate treatment can be administered is to do a skin scraping. This will reveal whether or not the culprit is a mite (sarcoptes or demodectes) or whether or not it is immune-mediated.
Ghilly
You can also do a google search for
Holistic treatment for mange....
Good Luck....and best wishes,
Connie
Check out this website.....
http://www.earthclinic.com/Pets/dog_mange_cure.html
.....it is long, but worth reading all the comments, and there are even a few photos of before and after treatments....
I hope this will help your dog.
Connie