Heartbroken over leaving for college

I'm heartbroken over the possibility of leaving 3 and a half hours away for college, leaving my three nephews and sister behind. I love my nephews more than I love anything else, including myself. I would die for them. I can't help but feel absolutely heartbroken at the idea of leaving for college, only seeing them grow up on video chat and through short visits. I one day want to move away from the area I live in, as well as my sister plans to possibility move to another state eventually, but now that the time to really consider leaving has came, I can help but cry. It's felt for years like if there was one reason to live on, it's them. They light up my life. But the idea of being accepted into this university excites me and his a whole new journey for a sheltered kid like me.

How do I deal with these emotions?