Hi,
We're sorry about the trouble with Photoshop. Would you mind telling us the version of Photoshop you're working on? Does the app run normally after you relaunch it or restart the computer or do you continue to see the flickering?
You can try disabling the option to Use Graphics Processor from Photoshop by going to Preferences, then Performance. Once done, quit & relaunch Photoshop to check if that helps.
If the issue persists, you can try to reset the preferences of Photoshop manually using the steps mentioned here: https://adobe.ly/3dFRlyi
Please backup your settings prior to resetting the preferences. You can check: https://adobe.ly/2vNz6FG
Let us know how it goes!
Regards,
Nikunj