Origin says Pets is installed but it's not showing up in game.

Let's set the scene: I was ecstatic to purchase Pets last month. I had high hopes and did not expect the palaver that took up an entire day. It took me HOURS to try and get the DLC to work in-game but Sims just didn't like co-operating. However, somehow it decided to work and not disappoint me further. BUT my game updated to 1.69 and that patch ruined my HQ mod so of course, I wanted to downgrade back to 1.67.

I uninstalled the base game and Pets stopped working? Now Origin is saying stuff like "Base game is not installed" but it is? 

Should I just update my game to 1.69 and then superpatch to 1.67? Or what else can I do to sort this problem game out?

(The pictures in order: what I see when I right-click Pets, Pets isn't in my Origin game folder but somehow it's in the EA one.)