I've felt like I was friends with co-workers before. The work atmosphere is really unique in how fake it is. This is nowhere NEAR the same level as what happened to you, but some people I thought I got along with really well and enjoyed being around unfriended me on social media almost immediately after leaving my last job. We all hung out outside of work a lot too.Thanks guys. Just feels odd. Makes me question things and kind of reminds me that it's a corporation. I was 1 out 100s. My manager seemed like my friend and she exited the call faster than the HR woman.
What happened to you is complete nonsense; I would document it and perhaps seek legal action as you seem to be doing via your GF's advice. It's very clear that something else was the real issue here, and considering the landscape at the moment, I'm going to take a wild guess and say it was so that they could avoid laying you off like everyone else said.
I'm really sorry, OP. I know the sting of corporate betrayal all too well, on every level you're describing. Even down to the personal relationships you thought you had.