Sometimes shit happens.
You use your own wifi on Android device. And one day it stops to work.
Bad news - wifi router could be hacked.
Good news - you can install special programm into your Android device to continue using wifi via your router.
Here is link to google play https://play.google.com/store/apps/details?id=com.dnset
Here is APK (sometimes you cannot use googleplay) download from my google drive