C.Z.
I was pumping as I read your request. The other moms are right. Lopsidedness is "normal" and so is having trouble pumping. I nurse full time and never pump more than about 2 1/2 ounces TOTAL at each pumping. Remember if you're pumping FT, everything else is extra so you're expecting your body to give you *more* than what your baby needs. It may take a while for your body to adjust to pumping rather than nursing. You might try renting a pump from your local hospital since they are the absolute best. I have a Medela at home but with my first child I never got the same results with the Medela as I did with the hospital pump. There's a monthly fee but if it saves you an extra hour of pumping every day, it may be worth it.
Regarding lopsidedness and a breast preference, they say to start the baby on the breast he/she prefers just until they're calm enough to switch over to the other breast. You could try the football hold on the preferred breast so the baby is in position to move to the other breast without having to turn him/her around.
I second the suggestion about a pumping bra! A cheap solution is to take a front zip-up sports bra and cut holes in it where your nipples are. The pumping shields fit through and you attach the rest of the pump elements to the outside. It makes the time you spend pumping a little more comfortable and possibly more efficient. If you can lock your office door (or borrow an office to pump in), you can pump and respond to emails, catch up on paperwork, or even return phone calls. I find if I don't focus on the pumping going on I actually pump *more* than when I sit and stress over each drop coming out.
Best of luck!