my baby had similar problems in the first month, I also need to use bottle to feed her but it made her confused with my nipple. she was using the bottle way to suck my nipple thus it's difficult for her to drink the hindmilk. However, she is getting better week by week.
for the milk flow, if you insist to let the baby suck, drink more water / soup and continue to pump, it would increase eventually. I could only pump out 2-3 oz in first month, but 7-12 oz in my 3rd mths, relax and don't give up.