I just feel so depressed?

So its all starting to hit me again. I met this girl three years ago and we became bestfriend sisters. We spend weeks at eachothers houses and we always had eachothers backs no matter what. She was there for me when I had some family problems and I was there for her threw hers. Well she lived with her dad and her mom lived across the country. We were bestfriends for two years and she went to go live with her mom for a couple months. I remember how hurt and upset I was because having someone and calling them your sister and doing absolutly everything to not seeing them for months sucked. She came back tho and we picked up where we left off and everything was back to normal. Then this summer she was going back to see her mom but this time her dad was moving there too. It was about a week before she left and she suddenly stopped answering my texts and phone calls. I saw her at her house one day outside so I knew she hadn't left yet. I asked her why she just stopped returning my calls and stuff and she said "you know I have trust issues and our friendship was to good to be true. But I now know what i did was wrong and I shouldn't have done that. I miss you." Since the summer when she left we started having contact again a few weeks ago. We text,skype, and phone call and everything is like she is still here. The problem is I miss her so much I don't have my besyfriend/sister here she is so far away. I just feel like breaking down and crying becuase I have no one like her to share everything with and just be my bestfriend. I might sound like a cry baby or whatever but I seriously just feel like nothing like i don't care. I just want to know why am I feeling it again since we started having contact again? How do I get over being so sad about it?