Can’t download the ea app and origin is not working anymore - can’t play at all

Hi, I’m not sure if anyone else is having this problem but since the sims has moved to the ea app obviously origin has stopped working. 

I play on a Mac computer - MacOS High Sierra version 10.13.6

every time I’ve tried to download the ea app it has a white no entry sign on the ea app icon when I try and drag it into the application folder. When I try and open it, it says “You can’t use this version of the application “ea app” with this version of MacOS. You have macOS 10.13.6 the application requires 10.15 or later” 

I can’t find a possible update on my computer anywhere.

So I basically can’t open origin anymore, because it’s shut down and now I literally cannot even download the ea app, so I’m stuck

is there a fix for this? I’ve spent so much money on this stupid game and now I physically can’t even play