Wife has checked out

We've been together and "best friends" for 15 years. Married for 7.

She dropped the bombshell 3 weeks ago that she wasn't happy and wanted to separate. It took me by surprise because I thought everything was great.

I've supported her so much over the last few years through a number of personal issues and she essentially said "thanks I'm okay now, so I don't need your support".

I think she was surprised by my reaction. Surprised about how much I actually loved her and how much I am prepared to fight for us.

She came round to the idea of trying to fix things but I'm getting the impression she's just biding her time so she can say that we did try. Every interaction I have with her leaves me wanting more as it feels like she's deliberately holding back.

It's absolutely destroying me.