I have been having these symptom for the past month:
-extreme fatigue
-isomnia
-low blood pressure
-feeling faint
-dizziness
-hard time getting out of bed in the morning
-irritablity
-sadness
-feeling weak
They are symptoms of depression, be careful.
It might be depression or that you're stressed. Although there are some things with those symptoms that aren't very healthy, so you should probably see a doctor.
Most of them are.
I would guess though that the insomnia is contributing to the exhaustion.
I am also not sure if sadness is a symptom of exhaustion.
best to get a check up with a PCP or GP