Hi Valerie
Henriette has some very clear advice on gallstones from Christopher Hedley on her site
http://www.henriettesherbal.com/archives/best/1995/gallstones-1.html.
I would echo Claire's suggestion that you ask if any of your local herbalists offer reduced rates for people on low income. If you live in Scotland, the student clinic and medicines are free. You could also find out if you have any herbal medicine students living near you who might want to offer you support as part of their studies (as long as they are being supervised).
Good luck!
Sarah