All I can suggest is make sure you are logged in to Facebook (save the password on your phone so it doesn't need you to manually log on). Once in swgoh , assuming it's back to the tutorial / starting account , go into setting and click "have account" and follow the on screen instructions to redownload the old account from Facebook. If this doesn't work , you will have to go through support to get access back which can be a challenge.
A second though. Do you have more than one Facebook accounts on your phone ? Make sure you are logged into the one you saved swgoh data with.