Totally agree with PR about no need for bf guilt for anyone, least of all those of you who have to deal with allergies and intolerances.
Fab news on the sleep Stunt. 
Enjoy the fresh air Sophia.
Pikz YANBU. Difficult situation though, I know I would feel awkward about saying I couldn't help out someone in need, even though I would be annoyed about the assumption I was available. Your friend shouldn't impose on you though. Perhaps the thing to do is to be quite breezy and say no, using all the standard MN advice not to give reasons for the no so they can't be problem solved for you. Good luck.
You'll always be Izzy to me, izzy Flouncy. 