Trying to keep a friend is hard work.

Ok, I have this best friend that i've known since kindergarten. We grew up together, but when we hit Jr.high we started to grow apart. It's not like we don't hang out we do and we talk and text all the time, but she wasn't sharing stuff with me. She would hide who she like from me- even though i could tell who she liked.
6,7, and 8th grade we went on missions to Kentucky together with other jr.highers. And she would tell her other friends stuff, but not tell me. So those friends, who were also my friends, would tell me. But if I asked her about it she would deny it saying she never said those things.
When we got into highschool-this year- she was stil hiding things from me. The last year in KY I got realy close to my other friend and startted hanging out with her more. So i was talking to one of our friends and she said that my bff of 9 years thought that I was replacing her with the friend that i got close to during the summer. The thing is I felt that she was doing the same with one of our friends. I used to go over to her grandma and grandpa's house with her every time she went over there, but resently she's been taking her other friend. I don't have a probible with her going over, or having other friends, but she was 'mad' at me for ''replacing'' her when I was giving her some space, since she wasn't really talking to me.
I put "mad" like this: 'mad', because she didn't say it to me. She didn't even show that she was mad. I wish she had come to me and told me, because she could never be replaced.
Another thing about her lying to me is that everyone she told the 'truth' to thought I didn't know she was lying, but I did. But every time she told me something, when she left a lot of people would be like "You know she's lying." I knew! But I didn't like them saying, 1. my best friend is a lier-even if she is. and 2 calling me dubm, nieve, what ever you want to call.
On the mission i told her how it hurt me that she was telling someone she just met things that she not telling me. I'm very emotional-well i'm a little beter now- and so that had me crying...And everytime i think about it i'm on the verge of tears. She like a sister to me and I don't know what i would do with out her in my life.