Pet rat broke my game

I have had a similar issue where the rodent's needs, especially hunger, get to very low levels but the option to fill their dish is never available and then the pet starves to death. I have not had any freezing issues.

Do you have any mods or custom content (CC) in your game? Could you test without?
You can just move the folder to a location outside the Electronic Arts folder.
If the game works without your CC and mods in, your issue is probably caused by a broken mod or CC.
You can find a full list of broken/incompatible CC and mods since game updated on November 13th over here:
https://forums.thesims.com/en_US/discussion/950909/broken-updated-mods-python-terrain-update-get-famous-nov-18/p1

This update, updated the coding for mods so most mods need updating.
If it still doesn't work I suggest taking out half of your mods and CC and testing the game. Then keep splitting until you find all that is broken.
Either update or remove the broken CC/mods.  

All of my mods were updated after the patch. Also I already said that I took out all of my mods. Even without my mods, my game is completely broken after the rat has died. I can't do anything except force quit the game because it's frozen and when I try to quit I get an endless loading screen. I think the rat dying has corrupted my save. 

I'm going to try rolling back my save to before the rat died and see if I can either sell him or try to save him from dying. 

I think the playable pets mod is the one that messed up my game. I rolled back my save and first played with no mods, and I was able to feed my rat. Then I put back in everything except playable pets because that's the only pet related mod I have (even though it shouldn't have anything to do with rodents), and again I was able to feed my rat so he won't die.