Trust me. You're only 18, you will have some great times and some crap times. Your look with change over the next few years, as people generally don't stop developing until they are 22-24.
Remeber, you are looking at your friends/peers from the outside, and to them they may be thinking the same thing as you. Just make sure you are doing what you want and that you feel mentally and physically happy in what you are doing.