@Griff77,
Your living situation may be more precarious than you think.
When push comes to shove, your BFF may end up choosing their partner over you--- regardless of how long you've known each other, BTW.
Unsolicited advice tends to not get a great reception. No matter how well intended.
I would suggest you look for elsewhere to live. And, not for nothing, but if you can afford to buy a house but don't want to live there, why not buy an investment property? It can become another income stream for you.
Why am I (unsolicited, heh) suggesting this? Because real estate ownership is a great way to build wealth. Renting just pays someone else--- no matter how much of a BFF they may be.