Whenever I go into build mode my tools don't show up.

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.