Slowed production

I need help. I’m getting really discouraged! For some reason all of a sudden I’ve stopped producing milk the way I was producing. When I pump I barely get half an ounce out of one boob and I can get 2 out the other. Depending on the time of day I might be able to get more out of each but my 4 week old is mostly unsatisfied when eating now. I’ve tried lactation cookies, body armpit, pumping After each feeding, power pumping, eating regular, nursing her on that side all of the time. She is nursing every 2-3 hours. Why am I not producing milk?! What can I do to fix this?! It’s getting to the point she almost refuses to eat off that boob all she does is cry on it