"screen time agent" is eating up CPU on activity monitor??

I would start by using Activity Monitor to kill the processes. They may restart automatically but this may reduce the amount of processor time they are consuming. Next, you should take a look at your Screen Time settings.

You have not included information on your computer model or version of macOS in use. It would also help to know if the version of macOS you have was installed by update or upgrade. To find the complete model information select About This Mac from the Apple menu. You can create a snapshot of the dialog as follows:

How to take a screenshot on your Mac

Capture, Save or Record Screenshots in Mac OS X - Help Desk Geek

OS X Screen Capture Shortcuts

(⌘⬆︎3) Command-Shift-3 Capture the screen to a file

(⌘⬆︎⌃3) Command-Shift-Control-3 Capture the screen to the Clipboard

(⌘⬆︎4) Command-Shift-4 Capture a selection to a file

(⌘⬆︎⌃4) Command-Shift-Control-4 Capture a selection to the Clipboard

(⌘⬆︎5) Command-Shift-5 Invoke new screen grabber

You can then post the image in the forum's message editor.

FWIW, %CPU and memory use are not the same things. You reported a problem with %CPU, then said the processes were using "so much memory."

Please read Writing an effective Apple Support Communities question. We are here to help. We are all users. We are not mind-readers nor clairvoyants. We only know what you write down and tell us. Be specific and thorough. Include your hardware information and installed version of macOS.