You might want to hold onto your vegetarianism outside of the house. If you go through efforts to get a grass-fed, humanely raised animal to eat, it's not the same as eating a grocery store animal. I don't know how you get your meat, but if you're switching over from vegetarian, I assume you make efforts to get the humane stuff. If you don't, call local farms and see if anyone sells some of thier cattle yearly or find out what meat processor they use and call that meat processor to get local meats from them.
Anyway, if you still have restrictions about what you are willing to eat, then don't confuse the relatives, ya know. If you're only willing to eat raw milk, then don't tell them that milk is ok, because you'll be stuck drinking pasteurized stuff. If humanely raised meat is ok, but not grocery store stuff, then you still won't want to eat what they give you.
So, maybe you can tell them that you've introduced a few things in your house because you're comfortable with where it comes from, but you'd prefer to only eat the animal products who's source is known to you. That'll save you from being served hot-dogs and slaughterhouse meat.
If you haven't found any sources, I'll tell you about mine.
Milk-Raw, ordered weekly and prepaid from a local source (check out WAP foundation if you don't already have a source)
Beef- I get it from a local farmer who only raises 100 happy cows each year. I pick it up at the meat processor. Their doors are open and anyone can see what's going on...very clean.
Pork (4-h club and the same meat processor. the meat processor is the same hunters would use)
Chickens (here's my weakness....I can't kill my own and I can't afford humanely raised.....I'm about to start killing my own this year)
Veggies come from the cattle guy and are delivered weekly.
eggs- backyard chickens
I hardly have any need to go to a grocery store!

The truth is that you were right to stop eating the unhealthy, horribly treated animals and products. But when you learn about other options, you change your choices. Just like your chose vegetarianism. A lot of people come out of vegetarianism and go towards TF. It's like an evolution. You hate the choices that you know about, so you opt out. Then, your eyes become open to other options. You might not ever learn about how to get humane animal products if you hadn't gone vegetarian. TF'ers are also people who've opted out.
Good luck.
Lisa