Is it irrational to have a fear of flying alone?

I am 15, and in 3 weeks I will be flying unaccompanied across the country for a summer camp. I have flown by myself several times previously, but those times I was flying as an "unaccompanied minor" so I was guided from terminal to terminal. I am a very nervous person typically, and I am convinced I will somehow screw this up and end up in Canada or something. I have been to some of the airports before (TUL and DFW) but I have never been to the Chicago airport (ORD) and have no idea what to expect. I did some research, and there are 3 terminals!!! I am sure I will become hopelessly lost and confused. Any advice?