Eucalyptus small tree?

my eucalyptus tree is about 6FT in a very large pot on my balcony, its been fine in gales freezing temp, until i went on holiday for 1 week, a lot of the leaves have split and gone brown, , i have new growth leaves too and the ends of these went brown too, any body have an idea whats wrong i've watered it well since i returned, thanks debbie