Plastic nut, would something as simple as band-aids help? How about those little velcro finger weight training things advertised in the mags? OR a narrower string spacing???
Fretless might be easier for you with really low action and thin (soft) strings. Peavy made a nylon stringed Brian Bromberg model a few years ago that you might find used somewhere if all else fails...
Try a good teacher first but thought these other ideas might help you... Good luck. Let us all know if you find a solution! Jim T.
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"When people hear good music, it makes them homesick for something they never had, and never will have."
Edgar Watson Howe
"Don't play what's there. Play what's not there" Miles Davis