Hi there and welcome
Can you power off the computer
Then power it on and on the sign in screen do not sign in.
Instead, hold SHIFT and with it held down, click on the power icon and click on restart.
Keep shift held down until the computer has restarted into a menu.
Choose Troubleshoot, then choose advance.
Choose system restore and follow the onscreen steps to perform a restore from the last restore point
Let this complete and when it has, tell me please if the computer is now functioning correctly.