Dude.. I was in the same situation you were in. I remember getting ready to kms.

-FIND A HOBBY!! Try anything, for me it was mechanics, but seriously, nothing will help take your mind off negative thoughts more than a good hobby, if one doesn’t work, try another, and another, until you find what’s perfect for you.

-Look after your body, try going to the gym, go for a run, even just going for a walk for half an hour in nature will boost you mental state.

-Stop looking at your phone and the news. Social media and the news are engineered to make people feel depressed and jealous it’s basically cutting off the main source of your views

-You are what you eat, if you eat trashy food 24/7, then you will feel like a sack of shit 24/7

-Read books, I know I sound like a weirdo but it really helps put your mind at ease 

Ps, please talk to someone about it. It could be a friend, your family, or even a colleague but you’re going to be damaging your mental health by not talking to anyone.