RNamw22 Please try playing in a clean user folder. Move the entire Sims 4 folder out of Documents > Electronic Arts and onto your desktop. When you launch the game, a clean folder will spawn with no content. (Your saves and other content will be intact in the folder you've moved but temporarily unread by the game.) Don't add anything to the new folder yet; just start a new save and see how it runs: whether you can create new sims or travel or switch households.
When testing, please do NOT use any content from the Gallery or your own library, at least not until the game is working properly again.
If the new save is fine, you can copy one of your old saves to the new Sims 4 folder and test that too. Since it's a copy, you don't need to worry about missing mods or custom content.