That's no good!
Have you seen a lactation consultant? Expressing can work, but breastfeeding is a lot easier in the long run. Getting someone to come to you to see what's going on and try and sort it out may be the best thing to do. In the mean time they can also give you advice on nipple care, expressing, etc.
The ABA can also give you support and advice, including info on expressing and storage of EBM.
Take care