So it's not the phone. You say it used to connect to your home internet but suddenly stopped - it's annoying i know when people suggest things or ask questions you've thought about for ages trying to solve this, but - I don't suppose anything's happened (upgrades, new wifi password) to the home...
Wish I could be more helpful, other than saying as it's two devices, you'd rather suspect the problem lies with the router/your internet provider.
How annoying for you. When you fix it, do tell what the problem was.