very sleepy

I have been very sleepy these few days..
 .. didn't sleep well.. didn't sleep much...
not in a good shape for the classes and discussions..

have to review and do assignment now..  but I can't drink milk tea... I drank a cup this morning.. i don't wanna overdose... and I can't drink it at night.. I don't wanna have insomnia

so... is there any substitute that might be helpful to wake me up?...
I made myself a cup of ovaltine. (阿華田)  
It tastes good.... but i don't think it helps...
...
..
.


Whatever ! ~
Study now.