You seem to be thinking that when you go to college, you lose your entire family. In fact, when you go to college you're adopted into a really, really large family. Your friends feel less like friends and more like brothers and sisters so don't think of it as losing your family; you're meeting new relatives you never knew you had.
If you do in fact choose to go to UVA, you will initially think that you'll call home everyday and spend hours on the phone with your family missing them and wishing you were back at home. But the fact of the matter is that this is the scenario for the first week, (maybe weeks) and then you realize that you can't waste hours at the phone. There's too much to do! Whether you're going to class, in class, eating, studying, hanging out, at a club meeting, or a plethora of other things, you'll find that spending hours on the phone is more burdensome than enjoyable. There's also activities on the weekends that you'll want to be involved in and you'll find that you can't go home every weekend whether you go to UVA or GMU. If you go to GMU and devote every weekend at home, you're seriously taking away from your own college experience. Right now, you're wondering how you could leave home. Once you leave, you'll wonder why you even thought about that.
Also, you talked about going to a good graduate school. A degree from UVA holds a little more weight than a degree from GMU simply for reputation; you have the backing of a school known for academic excellence. And if you're willing to work hard no matter where you go, then you should get the same grades if you're at GMU, UVA, Harvard, or NOVA.
Life is about meeting new people, seeing new places, trying different things. You won't always have a comfort zone to hide in, so come on out. It's pretty nice outside. Personally, I think you should go to UVA, but my opinion may be biased (just like everyone else here.)
Wherever you decide to go, best of luck in your endeavors.