Sounds like derealization.
Tired, hollow feeling and lacking spirit. Did I write this? LOL. But really, I understand what you feel like.
So you seek short term pleasures and stopped giving a damn about your image. I take it you're running on impulse right now.
Dude, this is textbook depression. Your brain chemistry is screwed up because your body chemistry is screwed up. Stress will do this either mental or physical. You can use drugs to get back to normal but they have side effects that are often worse than the ailment. The best thing you can do is find the sources of stress and eliminate them. In order to heal you should follow a healthier lifestyle. Get plenty of rest, vitamin C, vitamin B (helps with stress) and get rid of toxic people that are causing you problems. Also lots of fresh green foods. Get back to exercising because it has benefits but since you're physically run down then take it easy. Do some cardio, a little bit of light weights and that's it. Keep the blood moving but don't go heavy and add even more stress to the nervous system. It adds up.
If you ignore this and continue as you do prepare for it to get worse. I can tell you what happens if you try to soldier through. Your nervous system will begin to break down from stress. You will experience even worse derealization, acoustic and visual hallucinations like tinnitus or visual snow, muscle twitches and the next steps after are even worse.
Do something. I speak from experience. I have chronic depression running in the family. It sucks.