I have a few reasons why I gave up:
1. Traveling as a vegetarian is hard. It's difficult to find good options on non-vegetarian menus, especially in major meat eating areas (i.e. German-speaking countries and Midwest region of the United States). Middle Eastern & Indian restaurants are a good fall-back, but not always available and/or fair to my meat-loving husband. Not to mention the angst which happens when extended family members are trying to figure out where to go or what to serve for dinner.
2. We have an upcoming adoption. I was really, really torn regarding raising a child as a vegetarian. Children need a lot of protein and fat for brain development and animal products are the most efficient way to get it to them. Plus, being a vegetarian as a child can really set you apart, especially when you live in a Germanic culture. As an adopted, biracial foreigner, our child will already be "different." Not to mention that I firmly believe that to raise non-picky eaters you have to have everyone in the family eating the same thing at meals. And only eating that. Making special separate meals is a bad precedent to set. So making meat for my child and vegetarian for me goes against that.
3. My hair was falling out. Even though I very carefully monitored my protein intake, including doing a supplementary protein shake, I simply wasn't getting enough protein. The hands full of hair every time I washed my hair was disturbing. In the last six weeks, hair loss has slowed.
So I am once again eating meat, but I will continue to include vegetarian meals into the mix as well. We'll balance it.
Thus far my stomach is doing alright. Hopefully as long as I am cautious about what I eat it will continue to do so. Fingers crossed.