On the FarmUsa.org site you can read: "The biggest problems confronting America and the rest of our planet are disease, hunger, environmental devastation, and death. Every one of these traces its roots more or less directly to animal agriculture. Although most people are motivated by health concerns, it is important to realize that dietary choices have much broader implications for planetary survival".
Indeed, eating little or no meat is a significant way to reduce our individual "footprint" on the planet, and to make our own small mark to change the way farming is done and the way people eat. I for one buy organic for about half of the food I eat. Even if the cost for that is too high, eating vegetarian or low-meat (my own phrase) is helpful.
Changing one's habits, including eating habits, is often a slow or uneven effort. As in many cases, changing to a vegetarian diet likely requires some learning about nutrition, and about how to cook tasty and fulfilling meals with vegetables.
The effort to change habits may rely in part on associating with other people who support that effort, or at least are accepting of its value to you, and may also depend on finding good information to support the effort to change habits.
Changing behavior patterns can also depend on location, such as being near a farmer's market or a good natural food store, or having some land to farm, in the case of vegetarian eating. Sometimes individuals, couples, or families make hard choices and change friends, spouses, and/or locations so as to better support deeply held principles. I have seen each of those occur. Clearly such changes are an individual or family decision based on priorities.
I will write a whole article, or series, one day very soon, about the balancing of reality (jobs, income, habits, knowledge, preferences) with ideals (minimum carbon footprint, not harming animals, creating optimal communities, living in a peaceful or beautiful environment).