I've been vegetarian for about 12 years, and I came from a regular meat-eating family. Getting to where I am now, which I think is a pretty healthy, varied and balanced vegetarian diet, has happened in stages. I'm not sure how easy it would have been for me to jump straight from meat, potatoes and veg to beans, tofu and veg. I guess I would recommend getting to used to new foods and meals bit by bit.
When I first became vegetarian, I was relying on Quorn and cheese to replace the meat/provide protein. So really it was just a way of adapting the meals to become vegetarian. I don't think it was the healthiest way to be vegetarian (it's certainly easy to be an unhealthy vegetarian), but it probably wasn't any worse than eating the meat.
When I went to college I discovered more types of food and cuisine, and started cooking different things. There were more beans (chickpeas were a revolution for me!) so my diet was a bit healthier, and I mostly stopped eating Quorn. But overall, I think I still had a carb, and probably dairy,-heavy diet.
When I finished college and moved to the US about 5 years ago, I moved in with my boyfriend who has been vegetarian all his life. We started eating more beans, tofu, tempeh, lentils - basically quite a few things I had never cooked before. He doesn't like "fake meat", and in any case Quorn isn't widely available here. Plus, the only Quorn I thought was worthwhile were the "chicken pieces", and to be honest I'd rather eat tofu. While I'm not vegan, we do mostly drink soy milk, and eat a fairly modest amount of cheese and not much butter. We eat eggs every now and then but I only buy organic free range. Recently, I've started to think about going back to drinking milk and eating yogurt, but it would have to be from pasture-raised cows. Recently we started getting an organic veg box delivered every week, which has been a lot of fun - we're eating really healthy interesting meals, and trying out veg we've never bought before!
Some tips I would give you:
-Tofu and chicken can be fried separately, then added to stir frys, Thai currys, pad thai etc
-Tempeh is really amazing and flavorful (at least the one we buy). If you grate it you can use it like minced meat. We cook it in spices and use it in tacos.
-Chickpeas are awesome as a protein filler for anything - salads, Indian currys, risottos. And it's so easy, you just stir them in and heat it up for a couple of minutes.
-Hummus is your friend for sandwiches. Actually I don't eat bread much anymore (dislike American bread), but when I was in the UK I used to eat them a lot, and I was eating way too much cheese because that's the only thing I could think of using.