Welcome to the club! :)
I also recently went back to TS3 a few weeks ago. No matter how hard I wanted to play, after 10-20 minutes of TS4 I would get bored and just close the game.
I’m so happy that I decided to reinstall TS3. I was entertained for hours with just the base game and now that I’ve reinstalled all the EPs and SPs... wow! I honestly forgot just how much better TS3 gameplay is when compared to TS4. Now, I need to get the energy to reinstall my store content.
Granted, I didn’t go as far to uninstall TS4, since I have plenty of hard drive space and there’s just a shred of hope the game gets better.