Dizziness, Too Much Sleep And General Body Weakness

I have been noticing that I always feel dizzy, day or Night. I would sleep at the slightest touch of bed. I can't read for longer time as I used to and I am generally weak.

I use tonic, vitamin etc to no effect. I usually wake up earlier but now, I can't do that again. Please this affecting my study as I am now lagging behind. Can anybody help me?