@AusWeggieUnfortunately, you are not the only one who has this problem. Connecting to Gallery requires time, patience and many attempts. A lot depends on the speed of your internet but also on the number of objects in your library. When connecting with Gallery, your entire library - the Tray folder - also needs to connect with the Gallery.
It also helps to remove the cache folder from the game folder in Documents.
(Don't worry this folder will be recreated by the game once more after switching on the game)
You can enter the On-line Gallery.
https://www.ea.com/de-de/games/the-sims/the-sims-4/pc/gallerybut of course, you need to choose the page of Gallery with your language version
I don't work for EA
