How do people do anything?

I never have the energy (physically, mentally, or emotionally) to do anything productive, but I see people around me doing so much and it's just mind boggling to me. Last semester a girl in my class worked full time while taking 16 units AND partied a good amount, while I was just going to school part time and barely getting by. I have like 4 procedures I need done (life fucked me in the health department), I need to find a job, and I have general miscellaneous adult responsibilities, but it's so hard to bring myself to deal with any of it. On days when I have school I feel so exhausted afterwards I just lay in bed, and on my days off I feel so emotionally drained I just can't bring myself to do any of it.

I hate that I feel this way, because in so many ways my life is so damn easy (don't have major financial issues, don't have dependents, and I have a good memory so I can get by in school with minimal studying), but for whatever reason it's just so hard for me.