What you're experiencing is a phase of life, because from your post it's obvious that you're young, so I want to let you know that you're not alone, most people passed through that stage, it's probably depression, because things are not working out for you the way you've structured your life. It's good that you're opening up about this feelings because you'll feel lighter as you do, what I'll tell you is that you need to be strong bro, tough times don't last but tough people do, if you continue in this path, you'll probably end up a drug addict or worse become suicidal. Get a hubby, engage yourself in a recreational activity, maybe choose a sports, join a gym that you'll be active in, and let your loved ones know what you're going through. I hope that you'll meet that special woman that will make feel loved and feel good about life.
no doubt having positive mind can positively improve your overall health, I know guy fighting cancer all the time but they are always so determined they would get well and get back to what they love again, but what they failed to see is they didnt know their body have injured, their positive mind has fool their body too much until they cant stop working until their body failed again, that is why I said, life is about NOT TO DIE, but many people choose to die because they got brainwash into fighting a vietnam war that they cant win. I'd like to say you hage to balance you mind with both positive and negative mind, this way you could lead a balance and well happiness life.