New iMac freezing every click
First things first: Always backup your files!

I would start narrowing down the issue, i.e. trying to find the actual cause.

Run First Aid multiple times on your hard drive and see if it is able to repair the disk. You should also try running it in recovery mode.
Save your data before doing this: Uninstall the Adobe Creative cloud completely and delete all Adobe files. If this solves the problem, copy one file at a time back onto your iMac. By doing so, you should be able to tell which file may be causing issues.
Not clear from the question Check if certain programs slow down the machine, e.g. the Adobe Creative Cloud or something else in the background. You can check current processes in the Activity Monitor app.
Reset SMC and NVRAM/PRAM
Check if the problems persist in safe mode
(run Apple hardware test)

Check the different startup modes.
Making a clean install (preferably with an USB installer) is always an option, but will only solve software issues and should not be needed after 6 months.