I had a very difficult nursing experience with my first. It sure can hurt! So I ended up doing a lot of pumping. I kept supply up by always continuing to pump for 5-10 minutes after the milk stopped coming. You could also drink "mother's milk" tea. I don't like tea so I didn't do it myself but most of my many sisters-in-law did and had great success keeping (or getting) milk supply up.
yes you will loose milk if you don't put the baby to your breasts.
I have heard that if you only pump that your milk will dry up. I think that's what was happening to me because I chose to only pump and my supply just kept dropping.