Open Question: No energy, dizzy, loss of appetite; what could it be?

So I've been feeling sick lately.. Symptoms include: loss of appetite, always tired and never feel refreshed from sleep, can't fall asleep easily, random dizzyness, constant headaches, sore all over; joints, legs, muscles, random days where I get diharrea, short funny feeling when breathing. So that's pretty much it, or all that I can think of right now :) So yeah it sucks as you could