Why can I not connect to my wifi network? 8.2 iPhone Six Plus

As the question states, today I wanted to connect to my home network, I cannot connect to the 2.4ghz or 5ghz network. I have noticed bad network connectivity over the last month, hence why wifi was off as I was using my cellular data.

My wife iPhone (8.1.3), Daughters iPod, Windows 7 Laptop, Win 64 Desktop and iMac can all connect with no issues.

I always get an "incorrect password" error. The password is not incorrect.

I have reset all router settings, hard reset my phone, powered down the router and my phone for a few hours. Reset network on iPhone. All to no avail.

Please advise what the issue is.