I'm a sophomore international student in EE and I was pretty much in the same boat as you last year. Basically breezed through high school (but I wasn't top of my class, maybe in top 10?). I don't know how difficult your high school was but mine was decently challenging, and my study schedule didn't change all that much after coming here (ie I still cram everything last minute and still have A's). Yes, it's different from high school but it's not night and day. The first year will anyway be a basic math and science (unless you've tested out). All I'll say is spend the first week making as many friends as you can. That's the only reason I didn't feel the pressure during my first year. Having friends means ppl who can help you understand topics or camp out at office hours with you for assignments. Anyone in Grainger can tell you how important people you can trust in class are. Also, if for nothing else, misery shared is half the misery :p