I get anxious about anxiety - but only because I mistake it for other things :) at the moment my anxiety is also focused on my mental health... so we have some things in common.
Change is highly stressful. Indeed, it is times of societal change that produces higher 0119 rates - this is something that was highlighted by Emile Durkheim. Whilst Durkheim was using this statistic to indicate how society functions as an organic entity - a macro societal power that holds us all to account in one way another - it is useful to think about it, also, at the micro level of the individual.
If social change causes social anxiety, then personal change can cause personal anxiety. After all, society is just an aggregation of individuals (any social scientists out there feel free to challenge me here).
So it is not unreasonable that change should cause anxiety. We cannot be blamed for feeling increase levels of anxiety in these times. The irrationality here is not in feeling anxious when you arrive in the USA, the irrationality is feeling anxious about feeling anxious (something you seem to already be aware of). But I will say this: it is fine if you arrive and you have nerves - it is normal of any individual; it is fine if you are anxious at your first day of school (college/university? I don't know... I am English); it is okay to freak out a little bit here - it is not something that is outside of the human condition. Anxiety is fine, it is just not fine in the doses we sufferers are subjected to.
As anxiety with change is a probability even for the non-sufferer, you should just accept that you will most likely feel anxious when you arrive. However, you should not extrapolate that anxiety to the rest of your 12 months - people take time to adjust to things but you will soon settle in. Do not worry about worry. And when you do worry as a result of change, do not assume that worry exists as part of your 'condition' or that it will continue unabated for the remainder of your schooling.
I hope this has helped... it may seem like I am just cementing the thing you're worrying about to be true, but what I am trying to convey is that in these situations it is okay to worry a little bit
