I just want to know WHY. I do like everything I am supposed to do, still I feel tired almost all day long... It's to the point that it's really difficult to exercise. It's even worse on weekends, I am not able to do most basic stuff. I am mostly just lying in my bed.

Just.. What is it? Is it my anxiety that i am feeling almost all the time in my chest and upper abdominal area? Is it overthinking, am I just pretending? Is something overly wrong in my brain/body? 

What could it be??