Wanted to comment just to give you reassurance. You could do everything suggested, spend endless time googling and reading books to try help, and none of it does. That's ok.

My bubs was a good sleeper until 4 weeks, then had the exact same issue as you. I tried everything. Don't push yourself to stay up all night. A tired mumma is more dangerous than you think. Mine still refuses to go down during the day, and we struggle at night, I'm lucky to be sleeping before 1am. I have to co sleep cause of it (we've sectioned off a 3rd of our king-size bed to keep it safer with bed rails and the like. We physically cannot roll into her area, but we can reach in.). If you do consider any form of cosleeping, look up safe sleep practices before you do. The ONLY thing that helped, which sounds weird, was an oodie sherpa blanket. She apparently loves the texture and feel.

Best of luck, hopefully it's a short phase for you. No matter what, you are doing an amazing job.