You need to make sure the pump is latched correctly to prevent chapping, and I dont know if the pump you got has settings. But alot of the electric ones have different settings and will even save a certain suckling pattern to mimic the babies pattern.
Some people suggest warming your breast with a warm towel or cloth too, and drinking lots of water while you express to help with the successfullnes.
Some people find the hand pump work just fine or better too. It depends on how much pumping you actually will be doing, I will be pumping for going out and having company, and also for my OH to enjoy the feeding too. I wont be breastfeeding at all though.
From what i've been told and read on here, breastfeeding is painful and tiring also... So either way!