Sick vegan? ... what to do?

You'll be fine. When people, vegan or not, get the flu, their appetite decreases and they only eat toast & juice. It's not like non-vegans force down a steak when they're too sick to want to eat. If you're really concerned, get your boyfriend to make like 2 blocks tofu scrambled up deliciously for you, then just reheat small bits of it in the microwave. And keep it up with the smoothies/juice, that's really the best thing you can do. Hope you feel better soon!