A pretend friend

Recently I've been having a hard time at work. I've had to adjust my trust radar a few times.
I trust easily and 'over share' and that often means people think they know me very well. In turn they tell me things, I know a lot about people very quickly.
I'm thinking of all of this because there has been a new face at work, she posed as a friend but I get the feeling it was far from real. She used me.
I trusted, but now I am dumped.
I could be wrong, perhaps this is normal behaviour for her in friendships but it isn't for me.
Trouble is I could have done with a friend at work, someone who I could get support from. I've been struggling to be strong at work, to be in control, to care enough to be good at it. A friend might have helped a bit but she didn't.
Luckily I have a couple of people I can trust, and a few more who trust me. Can see the current me is weaker than normal and needs a bit of space.
More importantly I have real friends outside of work who are helping me get through this rough patch. Ones who check in, who keep me focused on what is important, who tell me their great news, medium news and bad so that I feel part of their lives and know I'm not alone.
I'm a mess inside. Work used to be my escape and it no longer is, well not all of it. Those great classes, who love to learn and we have fun together, they are an escape. In fact no matter how shitty things get, a great lesson can make those spirals of shame, fear and loneliness pause and retreat.
Her falseness is troubling me. I wish I could let go. I don't know why but I'm guessing it is connected to trust. To feeling used. It's all fine when you're needed.
My true friends are there no matter what.
I hope I am a true friend. Maybe that's what I'm troubled by; could I have been that false.
Yes.