You are getting good advice here guys. School is most important.
However, it is equally important that you visit the school you want to attend, and talk to the director of the program yo want to study (and maybe other professors as well in that department, if possible). Talk to students (upperclassmen only) who are close to graduating in what you want to have as your major.
Don't just fall in love with the name or prestige of your selected school and go in blindly. Try to get the best possible fit for yourself.
I'm also going to add another point that at least one other person has alluded to: Running in college is not the same as running in high school. It will be more like a job. All the crummy runners will be gone and it will be more intense, more competitive, and not as frolicky or whimsical as high school can be. I LOVE running. I'm 47 years old, still running (over 100,000 miles in my lifetime) and I've got four kids myself now to put through college. If I had it to do all over again, I'm not so sure I would run on a team this time (I did before). Maybe I would just run on my own, like I do now. Once or twice a season you can jump into a home college meet in each of XC and track as unattached without being on the team. I actually did that even after I graduated (for a year or two).
Here's another thought I would like to submit for your consideration: You can always run as a grad student. Maybe just go to college that first year and make your adjustment to big-time academics. You could run your senior year, then go on to grad school and run there perhaps. It's something to think about. You'll be older and faster and better able to compete.
You could end up being really good at running in college. High school isn't indicative of any future success. You have to decide how important it is to you to run competitively on a school team, and if it is important, you should try to understand why it's important to you (self examination). You're going to have to dedicate a significant amount of your time to it if you join the team. You won't have the regular college experience. Many of your friends will be other runners. You won't have the time to hang out in the dorm and be as carefree as others will be. You will have to be focused. You will have a lot to do everyday.
I stopped running during my junior year of college. I was a music major. I began performing music in restaurants (for really good money actually), and I got great experience in my major. I remember thinking, "I should have been doing this all along instead of running." Perhaps you'll want to immerse yourself into your major like that and just run on your own. You will have to make that decision yourself.
Just don't expect your college team to be like your high school team except with older kids.