I assume the phone hasn't suffered an accidental bump or water damage ?
Have you been able to soft reboot your phone by turning it Off and then back On since yesterday when you couldn't turn it off ?
If this has not self resolved then Samsung apply a 2 year limited warranty on their phone's.
Have you definitely owned the phone for more than 2 years ?
If so then a Samsung Service Centre can still assess your phone and provide a costing for repair.
If I can be of any further help then please don't hesitate. Take care. 😎
Daily Driver > Samsung Galaxy s²² Ultra 256Gb in Phantom Black.
The advice I offer is my own and does not represent Samsung’s position.
I'm here to help. " This is the way. "