If you are suspecting a letdown/ boob frustration I would go with the zero flow line.
Rachel - I know you are desperate but please don't consider introducing solid food to an ebf baby who isn't even 4 months old.
There are so many reasons why this is not a great idea at her age. Take some time to read about why the recommendation to start solids is now 6 months (especially for bf babies). There are always exceptions to this but she is very very young.
http://www.kellymom.com/nutrition/solids/delay-solids.htmlEarly solids is especially not a great plan if you have any concerns about weight gain. At her age it is extremely unlikely she will have the necessary enzymes to even digest the solid food effectively and as it passes through her undigested it will fill her tummy reducing her motivation for milk and affecting your supply.
I know this all seems hard and you are scrabbling for answers. Reflux babies are sometimes a population who traditionally did start solids a little earlier (e.g. thickener in the milk) but now it's more the trend to control the reflux with medication (as we now know the benefits of delaying solids if you can).
SO
If you suspect reflux - get some medical advice and visit our reflux board ('Colic, reflux, crying').
Slow down the haberman feeder.
Consider getting a fresh point of view and phone a breastfeeding helpline. You may get someone new who gets you to think about things in a new way or considers something we've completely missed.
Good Luck (Sorry to bang on about the solids thing but I'd hate to see you introduce solids so early and suffer with reduced weight gain, digestive discomfort and even increased chance of allergies.)