I recommend reading this: The Tattoo - Boarding school isn't what you think
It might sound cliche, but as far as my boarding school experience goes at least, it's pretty much spot-on.
If you have any questions, I'd be happy to answer them. Deciding to go to boarding school is a big decision that will undoubtedly affect the rest of your life, so it's natural that you're feeling unsure at this point. This was my first year at boarding school, and there have been times where I've been unbelievably homesick and regretted my decision and so much and said I'd give anything to just leave, and there have been times when I've been so thankful for my time here. Overall though, I'm extremely glad I came, and have decided to come back next year.