Fenugreek, oatmeal, blessed thistle, glass of wine or a beer are all good ways to boost supply. there are a few prescription ways but i've never tried them.
Why are you unable to bf? Just curious, not trying to pry.
Couple of tips for pumping. Pump every 1-2 hours for 5 minutes each side. Most women get the most out of pumping within the first 5 minutes so it's just frustrating to go at it for 10+ minutes with little to no output.
Go in a dark, quiet place and/or...