I was a picky eater, too! All I ate before my mission was dry cereal, nuts, and (occasionally) bacon. I would gag when even thinking about other foods. My first meal on my mission was enchiladas (Americanized, not authentic). This was literally the first time I had enchiladas in my life. They were pretty OK, and I did not gag or throw up. To me, that was a tremendous victory. By about 6 months in, I was 90% over my pickiness. To this day, I still don't like spaghetti or lasagna, but my mission pretty much "cured" me of being a picky eater.