29 F - Struggling with recent autism diagnosis and imposter syndrome

This has been the hardest thing I've ever been through. I feel like I've gone through every emotion imaginable! 

I have very little motivation, especially to do any basic needs like cooking, etc. I'm also not excited by or enjoying any of my hobbies at the moment, like I want to play games or start LEGO or do a puzzle, but I feel so exhausted, and the feeling that I have nothing left to give, and the thought of starting these things feels impossible!

I get a full night's sleep, and I wake up feeling like I've never slept a day in my life. Getting through a day of work is incredibly hard. I'm pushing myself and masking myself to appear "normal" when I'm actually wanting to just curl up into a ball and hibernate!! 

All I want is to feel better, and I've been told the way to do that is to rest and recover, but this feels too alien to me. I feel like I should be physically doing something to be able to get better. I also feel like I've been resting for ages now and being kind to myself, but I don't feel like I've made much progress at all. I've had enough of this feeling and just don't know where to go next.

Any advice would be most appreciated?