I'm here in the UK too, I'm sorry to see you are here but I am pleased to 'meet' you. The first thing here is to not blame yourself, you haven't pushed her further away, she is doing a jolly good job of doing that herself and that is *her* choice, you have no control over that. You have to let go of the feeling that you can control her or make it better at the moment because you can't - at least you can't instantly. Be the best person you can be. This is going to take time, and a lot of it. It is going to be a rollercoaster and you need to buckle up for the ride if you want to ride it.
You have gotten some great advice and Puppy in particular is excellent. He has been through it. It is hard to implement at first because your instincts tell you it is wrong - believe me at this time your instincts are not going to draw you in the right direction - this comes from the girl who has made every mistake in the book before finding DBing.
She is saying that it is becoming harder and harder to live with you because she is not getting her own way - think of the way you would treat a tantrum throwing toddler here. She also conceded and went into your son's room - great job! If she wants this she can implement it. A wise DBuster said to me once.
" if someone wants to leave, let THEM do the hard work of tearing their life apart. So, I think there is a way to find a balance between letting him do the work AND not being an obstruction to whatever plans he may have "
How can you put this into effect right now in your situation?
I'm around all morning on the computer if you want to chat.