I can see your morning has not been very good... 
Aspirin is the best fast cure for headaches. Since you cant
swallow those tablets, I suggest you take the liquid ones
Yes,
there are for kids but aspirin just as well. You probably need to
take twice the amount. The are called Panadol
for Kids 
. You can get them from any mini-market or
7-11.
What about your diarrhoea. Still troubling you?
