distract yourself. this is the number one tip from me - distract yourself, and don't focus on whatever the hell you're feeling. it's never safe to keep going down the path of Depressing Thoughts, and you'll end up in the worst hell ever if you do.
go watch youtube. read a book. draw some art. have a bath. walk outside. do something that can get your mind off things
(anxiety) when you suddenly hit that paranoiac thought, stop it at once. stop it, dead end, period. don't think about it more. skip to another, better thought, and don't go back to it.
you can even focus on the tiny things in real life. like how the time is 1pm, and there are 11 or so hours to go until midnight. or how the clouds in the skies are ...