<human>: Can you condense the text into a few key points?

So me and this girl have been together coming up three years. She has social anxiety and general anxiety and I'm starting to think mild depression. 
The problem is I feel so unappreciated by her, it's starting to get hard to sympathise with her. I stay up with her late at night till she sleeps, I'm constantly paying attention to how she is, asking how she is or how she feels every few hours, doing literally everything I can to be there for her... But I feel like none of that matters. Just last night I asked her if she could maybe say thank you to me just once in her life for what I do because I'm feeling unappreciated and she flipped out and told me I was an unappreciative asswipe, and that I should see her talking as her 'appreciation' for my efforts. I don't feel like that is appreciation at all. She refuses to talk to me about this (we aren't talking atm). I read all her msgs and she takes screenshots of what I say and sends them to her friend and says she's done with my 'shit', and has big bitch ups about me but I'm not allowed to talk to my friends about any of my relationship issues. I don't know what to do anymore...
<bot>: feel completely unappreciated by my SO. Need advice on what to do when she refuses to talk to me about it, and then ignores my msgs after reading them