Fever and pains, craving drinks but water makes me feel sick. Anyone ever had this?

[ifaistos]

I've got what I guess is a bug - dc have been ill too. Apart from just feeling like complete crap with a fever for 3 days, I've got back pain so bad I can't lift 7mo ds. I'm really thirsty and craving juicy fruit (actual, not the chewing gum), bit like when pregnant, but drinking water makes me feel really sick. I don't get bugs much. Is this normal? How long should I wait with fever before seeing doctor? Sorry for moaning btw...