wrote: then I got no internet, and no connection to the EA servers
Right - That's ok, it still will help to troubleshoot what is blocking the game from opening. Origin will tell you you're not connected to the Internet; that's fine, we're just testing. If you click through the "error" messages, SimCity should open. If it does, you should get to the opening menu.
If you can open SimCity normally after a clean boot, then you can find which program is blocking it. It is a pain! Enable a few programs at a time, reboot normally and try SimCity again. Keep enabling a few programs at a time > reboot > try SimCity. Eventually the program will stop launching, so you know that one of the last few programs you enabled is the problem. Then narrow down from there.
For example, you enable 5 programs in the startup list and when you reboot, SimCity hangs on launch. Go back in to the startup list, uncheck one of the 5, reboot and check again. Do this until SimCity launches again. Whichever program you unchecked last is the culprit. Then you will want to leave just that one unchecked and check all the others again. Microsoft help explains it a little better, I think: *Edit - having problems getting the right link to it. Scroll down on the page https://support.microsoft.com/en-us/help/929135/how-to-perform-a-clean-boot-in-windows to the part that says "How to determine what is causing the problem after you do a clean boot" and follow the steps.
If you find a program that is blocking SimCity from launching, please reply back so we all will know what was causing the problem.