I didn't have D-MER, but I found pumping to be somewhat stressful and really tried to make it "me time." Do you pump hands free? I would always pick a TV show to watch on my Ipod that I loved and my husband didn't like, so it was an indulgence to pump because I didn't have to compromise. Maybe try setting up something like that, then get the pump set up? I actually found it less enjoyable and more stressful to look at pictures of my DS while i was pumping; it just reminded me that I was away from him and pumping.
It's a physiologic response so in someways there may be nothing you can do about it, though it's interesting that you don't get it as often when you feed your LO.
DS Ethan 12/16/2008
Breast fed/pumped 11 months as a surgical resident, 80 hours a week at work
DS Abram Daniel 12/20/2012
Feel like we've gotten a strong start