I left home for college at 18. I loved college and being on my own. I developed as a person, picked up employable skills and convinced my wife to marry me while away from home (30 miles). I probably didn't sleep well enough and I did have the luck of reasonably good health.
My simple advice: Be prepared. Take the personal responsibility to figure out what college life is going to be like. You'll need to prepare for the things that everyone prepares for (cooking, cleaning study habits, interpersonal skills), and then you'll need a couple of extra preparations for the CF stuff. Figure out how/when are you going to do nebs and PT, how you are going to get your Px refilled, and what you will do if you start feeling run down. You might want to start transitioning to an adult clinic and build your own relationship with the staff (let your parent tag along, but don’t let them run the show anymore). Talk and plan with your parents (again run the show so they know you are taking responsibility) and see if they have any other suggestions or ways they want to help you. Lastly, build a contingency plan so if you run into serious health/finance/social trouble, you have a soft place to crash land. Maybe figure out how to drop a class or take a semester off if your health needs attention (a college councilor might even be able to help you develop that plan). Make the plan while you are healthy so it is easier to execute if you get sick.
Leaving home can feel daunting but it is very rewarding. The things you’ve learned from fighting CF so far, will aslo help you fight through college and the real world.