I changed my apple id password and now Imessage wont activate.

I changed my apple ID password and now my imessage and facetime won't activate and keeps giving me the error message 'Could not sign in. Please check your network connection and try again.' I've reset the network settings,updated to the latest software, reset the entire phone to factory settings. I'm connected to wifi. I don't know what else to do. I have been trying to fix it for about 5 hours and I need help.