I also could never do the dream feed. Dd was exclusively breastfed (she wouldn't take a bottle at all), and I had trouble keeping her awake for feeds or feeding her at all if I had to wake her for a feed; there was just no way to get her to latch on. So I didn't do the dream feed. But with you needing to go back to work, there's just no other way to get some sleep so you can be functional! Can you pump a bottle of milk to give to her? I've read in other posts that you are giving bottles, so she might do better with a bottle, as it's an easier feeding action. I know you want to nurse as much as possible; maybe pump after each nursing to get as much milk as you can for that bottle? Do you do cluster feeds before bed? That might help her sleep a bit longer, too.
I feel like I didn't help at all.
Hope someone else has some more advice.