When I went Veggie, it was akin to giving up smoking; the body craves something that it's been reliably drip-fed, in this case animal protein.
However, the fact is that vegetable-based protein can be way better. Tofu, Humous and Quinoa are excellent sources of protein.
I buy plain tofu, slice it and pat the slices dry, then fry the slices in sunflower oil. Let them cool and they can be grilled to make a tough steak that a lot of meat eaters like for similar reasons that ex-smokers go for inhalers over patches. Marinade it in a mixture of soya sauce, brown sugar, balsamic vinegar and ground ginger and you can get a really tasty burger substitute.
Mexican and Caribbean food has loads of tasty meat-free protein dishes - rice and pea is excellent (and goes nicely with some tofu marinated in jerk sauce), and spicy beanburgers rock.
Quinoa is a south american grain which contains the perfect protein mix for a human diet - it's got every amino acid (protein building blocks) you need. Use it in place of rice, or even buy flakes, mixed with Millet flakes to make a high iron porridge (you'll still probably need an iron supplement once in a while).
Broccoli is a good iron source, too.
Oriental food is a good port of call; the large Buddhist population in the far east means that Thai, Chinese etc cuisine has loads of veggie options.
Humous can be made by blending cooked Chick Peas, sunflower oil, garli, lemon juice and Tahini (a paste made from roasted sesame). Again, this is an excellent source of protein.
All nuts are great sources of protein. Walnuts and Peanuts are really good for you and their oils are some of the healthiest available (sunflower and olive are also very good). Dry fry cashews in a steel pan and mix them with sultanas for a good high-energy snack to keep handy, or a great stir fry ingredient.
I don't know if US stores stock it but Linda McCartney makes a good vegan sausage. Fry any sausage and throw in onions, red wine and marmalade and it'll taste amazing.
After I went full on vegan and continued cycling daily, I can pour deep-fried food (using peanut oil) down my throat and still struggle to keep weight on. Chop up baby maize, make carrot fries, and tofu finger, and batter them in this - http://www.cdkitchen.com/recipes/recs/520/Kfc_Chicken_Secret_Spices31600.shtml
I second the above advice to lay off sodapops - the type of sugar used by the US soft drinks industry is really bad stuff.