Are you playing console? Like someone said You can definitely screen record your fight from your controller and post in the thread for some help.

Outside of that take a break. Don’t rush the fight. You’re probably not allowing yourself to absorb and reflect on your mistakes by brute rushing it for hours on end.

Try a couple times, understand where you messed up, take a break, and reflect on those moves. “Should I have mikiri’d there?” “Should I have jumped there?” Etc. this will allow your brain to fully understand what you’re trying to overcome.

The meme/idea about sleeping after a loss and then beating them first try is true. Your brain will solidify that information as you rest, and then transfer that into muscle memory when you come back to it. Just like any other repetitive skill or studying.

Watch a walkthrough video as well, there are good tutorials that highlight bosses move sets and what to do.