I'm not an expert at all, but have read several of these topics, and it seems the common thought is to take it really slow with them, give them the basics, and stop plenty of times to let them digest it the best they can, and ask you any questions they have. Try not to overload them with too much at first, it's huge thing for some people to wrap they're brain abound and accept.?
Even if you might not feel it went well afterwards, give them time to think about it, things often improve afterwards.
And if they accept you unconditionally, then I'm sure you'll feel as though the world was lifted off your shoulders, and be very happy.
We're all rootin' for you.! 🙂