The only remedy for me was time.
I'm sure you remember what I was like just over a year ago, feeling trapped, feeling hopeless, so worried if I was going to be accepted, if I was going to be seen as anything more than a freak by people.
Well, unfortunately, there was no magic switch that made those feelings stop.
The only thing that made them go away was me just basically deciding that I'd had enough, that I couldn't stand all of the self-doubt that was coming from that seemingly-unscalable wall of having had introduced myself to people as a guy and then needing them to suddenly accept me as a girl now, so even though I still wasn't confident in my passability, even though I was still getting stared at sometimes, and even scoffed at, I decided that I had to do it, otherwise it was never going to happen.
Even that didn't completely solve it. It took me 4 months of searching, doubting myself the whole way, before I finally got my first post-transition job. And even after that, it took me another 3-4 months of near-constant worry, constantly hung up on whether I was passing or not, hung up on my brain spinning around in circles over whether other people were judging me, whispering about me behind my back, secretly laughing about me being a freak, before my anxiety about being trans FINALLY eased, and I was finally able to start relaxing and just living my life again.
It takes time. And unfortunately I think that the only way to really get over this kind of anxiety is just through continued exposure, over months and months and months, until finally you slowly stop worrying.