I just found out that my best-friend of 4 years is moving away.

My best-friend of 4 years is moving away with her family to be closer to her relatives and I seriously don't know how to feel. I feel so upset and lonely all of a sudden. We've talked about her moving before but I never thought the time would actually come. She's my best-friend and the only person I trust with anything and everything. It's not like she's moving far away, it's an 8-9 hour drive away from where I live. But I can only go when I'm on holiday and even then it's expensive to go. I feel like no one understands how I feel. I share everything with that girl, we even go to school together. Her family treats me like their own and I literally can't fathom a life where I don't get to see her everyday. Four years may not seem like a lot, but with a best-friend like her, it feels like 10 years. What do I do with this feeling of loneliness? How do I manage my emotions?