Welcome @nuala Sleep, or rather the lack of it, is a constant refrain here hence the existence of Night Howls - somewhere you can chat or rant in the early hours (or anytime, really).
Bugger about the trip but unfortunately this does take priority. That's great that chemo hasn't had to much impact on you. The tiredness thing seems to be cumulative and it doesn't help when a solid sleep eludes you. I'm 13 months from diagnosis now and I'm just starting to sleep the night through. Not this morning though - combination of heat, hayfever and back to work after Christmas I think!