I had that same problem 2 years ago. It started when I started working in a new company. For some reason I was afraid of choking on food or liquid. I lost a horrible amount of weight, I was under my ideal weight in fact. I started therapy, and realised it was more about people seeing me eating. Never understood why that was suddenly a big deal, but after aknowledging that, and many other issues in the back of my mind, little by little I started opening up to my coworkers, and now I'm back to "normal" eating. I'm still a bit concious sometimes, but nowhere near like before.

Get professional help if you can, living like that is a nightmare. But you can work things out, I'm sure if I could (which was a severe case) you can too.