Cannot connect to wifi on my iPhone 5 after updating to iOS 8

I have just updated my iPhone 5 to iOS 8 and ever since I have I cannot connect to my wifi because I get a notification telling me the password I'm using is incorrect.

I know it isn't because I'm using the wifi on my computer and the password worked just fine.

I've tried reseting the network settings, reseting all settings and even reset my phone to factory settings and nothing has worked.