phone won't connect to my house wifi?

[AC Question]

I've been trying for days to reconnect my phone to the wifi after it messed up, but every time i try, it comes up with "authentication problem" or "obtaining IP address" for a few minutes. Due to it not connecting to my wifi, my phone has used up all of my mobile data and i can no longer use any of my apps, as they need the internet to work.
Back with the wifi;
I have tried forgetting the wifi and connecting again, that didn't work.
I have rebooted my phone, tried connecting, but still nothing.
I've tried everything that has been suggested on websites that i have looked on, but unfortunately nothing has worked.

has anyone got any solutions as to what i could do?

 

[RumoredNow]

Have you power cycled your modem and your WiFi router? Turn them both off for two minutes.

Boot up the modem and let it cycle to completion of set up. Boot up your WiFi after that and let it cycle on. Then connect to your WiFi via a laptop or other computer on your home network (your WiFi manufacturer can tell you how to log on to your router) and check the settings.