How can I get my WiFi connection back?

Try disabling WiFi in settings. If that doesn’t work, click the “i” in the circle next to your saved network and then select “forget network”. Toggle the WiFi on/off button again, then try to connect to the network. Type in the password and you should be good to go. If this doesn’t work, you can erase all network settings (do a backup first). Then try reconnecting.