You are not cruel at all! Jasper is getting the care he needs - now you need to take care of yourself so that you can continue to be the mommy he needs. And pumping is such hard work, and very emotional - do whatever you need to do to make that work for you. :)
Just out of curiosity, is your back pain in your upper back? I had horrible back pain after my c-section, and I was afraid it was from being in bed so much, but the nurse told me that it is referred pain from air that gets inside during the surgery. It migrates upward and irritates nerves, causing upper back/shoulder pain. Not that it makes it feel any better to know this, but I was glad to know that I wasn't going to develop a back problem on top of everything else, and it did go away completely after a few days.
Also, Percoset, while great for pain, gave me nightmares (really vivid, bad ones) and made me itch. I switched to Norco and felt so much better.
My pain is mostly in my lower back, I have a pinched nerve from a accident in my youth and it does not agree with being bed ridden lol!
I actually switched to a smaller flange today and my production has double so Im really excited.