How bad would it be for someone with aspergers syndrome to move from England to America? (as a young adult)?

My girlfriend wants us to move to America when we move out to find a place together because she'd like the change, but I feel really bad about going because of said change... the only other country I've been to is Spain as a kid and I spent a lot of time inside and never strayed beyond my comfort zone. The idea of getting a place together and dealing with all the newness of bills etc is pretty daunting itself, but doing it in another country where there's no-one else to help out if it goes wrong and no familiarity around me at all (aside from my girlfriend). She understands this and said it's ok for us to live in England because of my aspergers, but at the same time, I don't want to let her down because she's the best thing that's ever happened to me. So the way I see it, it's either go to America and potentially mess up horribly or at least suffer from the drastic change etc, or live in England in my comfort zone and carry the guilt of knowing I'm holding her back for the rest of my life... what should I do? D: