I'm not an expert, these are just things I'd try. Skin to skin but with her head towards right boob so she hopefully finds the boob herself. Positioning, so if you usually use cradle hold, hold her in rugby hold so she gets tricked into thinking it's the left boob she's feeding off iykwim?
Would breast compression perhaps help? There's info on kellymom I think or maybe expressing of a small amount to start your let down reflex before she latches on so if there's milk there she might fuss less.
I can't help with the supply, sorry although I do know pumps are less effective that babies so she'll be getting more than you think.
Lancashire Sling Library www.lancashireslinglibrary.co.uk
East Lancashire and surrounding areas sling agent for www.petitpoppet.co.uk