Hi K.,
I had a similar experience and I'm very average in terms of breast size. However, I was able to work up to 6 oz of pumping after while (as other mentioning, relaxing is imperative). So, I was able to get just enough to get my older son through those early weeks of back to work. I also was able to visit at lunchtime and nursed then. And, I made sure to nurse first thing in a.m., when dropping off, when picking up (before going home), as soon as I got home, etc. So, you can adjust your schedule to just nurse as much as possible to minimize the amount of pumping. I ended up not pumping at all with my 2nd because he refused a bottle, so feel lucky that isn't a problem for you ;)
The big thing that I had to be aware of overall is that my milk supply would decrease during the week when I went back to work. To make up for that (and to rebuild the supply), I made sure to spend extra time nursing on the weekend.
So, don't give up on the nursing when you go back to work -it gets easier once they start solids and once my boys did, I just reserved the solid food for when they were with the caregivers. They didn't really eat much solids at home until they were almost 9 mos old. And, for me that nursing was a good way to reconnect after the time away. And, I know how very, very important it was for my boys. When they transitioned my 2nd son out of the baby room, he was so distraught until I came at lunchtime and he realized he could still nurse - he got that "all is right with the world" look on his face as soon as I sat with him on his nap mat and we nursed.
Also, although it might be a pain, continuing to nurse at night for a while is one of the most helpful things you can do to maintain your milk supply. And, it is not at all unusual for a baby to want to nurse more often at nite when Mom works - they naturally want to make up for the time away during the day. For me, the biggest thing that helped during these early days was reminding myself that it really was a very short time in the bigger scheme of things.