Blood sugar / glucose monitor?
Sorry to add to the wall of text...but I can clearly remember in my teenage years lying under a car attempting to work on something and just lying there staring at stuff for a long period of time, not wanting to move.
As a child I was NEVER tired at bed time, but I was ALWAYS dead tired when I woke up in the morning.
Those were signs.
For about $30, the OP can get the wal-mart meter, lance, and 50 test strips.
Do it.