Lori,
Not being able to pump at work sucks, but you can continue to breastfeed, even if only "part time" if you can't pump at work. I've been back at work full time since DS was 3 months old. I have never pumped at work (we have 1 faculty restroom-and a staff of 30-I wasn't EVEN going to spend 20 min at a time in there). I pump right before I leave and as soon as I get home (when I'm pretty engorged, but what can you do?). Doing this I am able to provide all the breastmilk DS needs even as a full-time working mom. Now, it all depends on how well you respond to the pump and all, but if you're lucky and have a good pump, you can do it without having to pump at work. It takes some uncomfortable times of getting your breasts "trained" but it is worth it!
Just a thought.