My macbook is eating RAM memory

For future reference, please make sure you are not stressing over something that changed over seven years ago. Starting with macOS 10.9 in Oct 2013, Apple re-engineered its RAM allocation scheme based on the principle that “unused RAM is wasted RAM.” "Free RAM" may be good for Windows but the current metrics for Mac RAM evaluation changed in 2013 to "Memory Pressure" and "Swap Used."

Using Activity Monitor's† Memory tab (in Applications >Utilities), if Pressure is in the green and Swap Used is zero or nearly so, everything is working normally.

This screenie is from an older iMac after updating to OS 10.9 and the new RAM scheme. Note how much of its installed RAM was being used, yet the computer was running flawlessly.

Here is an Apple support article on the subject: View memory usage in Activity Monitor on Mac - Apple Support

And another: Check if your Mac needs more RAM in Activity Monitor - Apple Support

If you are still worried about RAM usage, all you need do is to restart the computer once a week or so.

† — For best results, set Activity Monitor's "View" option to "All Processes."

You need to uninstall CleanMyMac and enable Mac's built in security.

Your battery needs servicing.

You have adware that needs removal.

You seem to be launching a lot of apps/services on startup. Reduce this number.

There is nothing wrong with your RAM use.