Why am I puking mucus with my food every time I eat?

[17jhamm]

I am a 19 year old female, and starting a little bit more than a year ago, I feel as though my body rejects all food. In October of 2016, I got my gallbladder removed after months and months of not being able to eat anything. I lost 40 pounds, and spent many days in the ER, and had just about every test done. I had a gastric emptying study, a HIDA scan, upper endoscopy, CAT scan, blood tests, food elimination diets, etc. After my gallbladder was removed, I had troubles eating certain things, but it wasn't too awful for a while. Starting a few months ago, though, my body began projectile vomiting everything again. I know when I am about to throw up, my stomach burns and I feel like it needs to happen, and when I throw up, the food seems to be encased in a mucus-type sac almost. It's very disturbing. A month ago, my doctor decided to put me on a gluten free diet, and while this seemed like a good idea, I cannot eat anything. I'm essentially a medical mystery, and I am wondering if any one else has had any similar situations. I'm really struggling right now, as I am a very active teenager (playing very competitive softball) with no energy to do anything with the lack of calories I have been in-taking. Any help would be very much appreciated, thank you.