this is where knowing yourself helps. if i were in your shoes at the moment, i would eat, and i would eat anything that sounds even remotely not unappealing. so if bread seems okay to you, eat bread. if a plain baked potato sounds good, have a plain baked potato. if nuts and seeds seem okay, have nuts and seeds. but i have also learned that when i feel nauseated, as long i have been able to hold down water for at least four hours, eating helps me feel better. because nausea doubles as "can't hold food down" and "should have eaten hours ago. SOS!" at least for me. and i only learned that by trial and error.
remember that while calories are important so is getting the nutrients you need, our bodies were designed to take being sick every now and again. you should really worry if this happens every week or more frequently, but the odd day here and there isn't going to throw you off. it's when the odd day becomes every day that you have a problem.
so when you are sick, eat what you feel you can manage. don't focus quite so much on getting the exact balance of where you should be that day. if you're really worried about it, average your week with the odd day out. odds are it will be in range on most things on average. and that on average being where you should be is more important than the little blips here and there.
-google first. ask questions later.