I've been awakened in the night with symptoms.  Ugh!  

Our bodies produce more histamine at night and in the early morning hours than during the day.  Asthmatics often have night attacks because of that.  If you can take a longer acting antihistamine a little later in the evening, it might help.  Have you tried Nasalcrom nasal spray or Astelin?  Nasalcrom stabilizes the mast cells in the nose and Astelin is a nasal antihistamine.  One of those might help.

Remember, just because it happened once, doesn't necessarily mean it will happen again.  Keep your meds next to your bed, in case you need them quickly, though.