First, let it set in. Like really just think of nothing but how bad you feel. Think about your situation in the worst possible term. Exaggerate everything. Lost your job? Think “THERE IS NO POSSIBLE WAY I WILL EVER FIND A JOB. I AM UNQUALIFIED IN EVERY WAY AND EVERYONE HATES ME.” Can’t get a date? “I AM UNGLIER THAN THE ELEPHANT MAN.” Running out of money? Google “Cricket from Always Sunny” because that’s your future.
Eventually you might get a little smile out of it. And that’s when you get to take baby steps to pick yourself up. If you can’t force yourself out of bed, just start rolling around a little bit. Hungry but can’t cant bring yourself to eat? You already think you’re a piece of shit so order the most disgusting thing you can think of and have it delivered. Eventually you’ll get your strength back to throw it away. Finally feel like talking? Find a friend to vent to and wait till they get so sick of your shit that they force you to go to a therapist.
Baby steps and never stop finding things funny.