Jamie, this sounds like a problem which some players are experiencing since the IP expansion pack.
Try making a shortcut to bypass the origin login and staying logged out until you have started your new household.
To do this, you right click on your desktop and select "new".
Then "shortcut".
You will then be asked to "browse" to supply the path to the shortcut.
You will need to create a shortcut to the file TS3EP10.
If you do not have IP, you will need to create a shortcut to your last installed EP. The file you will need will be TS3EPx where x is the number assigned to that EP. If you do not know the number, you can find it by examining your games folder and finding the file which starts TS3EP.
The shortcut will place an icon on your desktop labelled TS3EPx. Use this any time you want to start a new game, or place a new family.
I hope I am right that this is your problem. Give it a try. Good luck.