iCloud Photos taking up all my Mac Storage Space

You don't say which operating system you are using-- is it Ventura?

If you look at Photos>Settings>iCloud, do you have "Optimize Mac Storage" checked. This will keep full sized images at iCloud.com and smaller, screen-sized images on your computer, saving lots of space. (It cleverly only changes to smaller files when you begin to run low on storage, so you may not see an immediate effect.) When you need a full sized image for printing or editing, Photos will grab that from iCloud for you-- you never really notice the difference.

Get an external drive, format it to APFS for SSD and OS X Extended (journaled) for a rotational drive and move your library to it.