Missing friends.

So, the most dramatic issue in my life these past few years is the horrible feeling when you lose a friend. Not as in them dying but, just not hanging out anymore.
All the way to 6th grade I only had one friend. Tiffany. It sucked though, cause she had other friends.
Well at the end of 6th grade I got some really cool haircut, and I guess turned "hot" in guy's eyes, then BOOM, 7th grade I get soo many friends for the first time, and it's not just friends of Tiffany's, these people actually liked me for me.
It was all very new, but little did I know that it only lasts for so long. First, it started with Tiffany. She got her first "real" relationship which caused her to act like there was no one else in the world besides her and her boyfriend, Marshal.
So, because of that I became very close with my other new friends, like Emily and Jake.
Jake and I dated for like.. a week, but it wasn't really anything. After that though, we got so close and were like best friends.
Emily and I hung out almost every day, talked about everything, we were really close.
Here's how it is now -
Now Tiffany and I are still pretty close, but she will only hang out when she's single, which I've come to accept.
Jake and I don't even talk anymore, barley. It's so weird because I don't know how or why it faded away. It happened all a sudden and I don't even know when.
Emily got into her boyfriend who did major drugs, drank, and it changed her so much. Now she's like dead to me she's such a different person. She smokes weed everyday now when her and I used to talk of how, to us, it was a stupid thing to waste money on. She even did it once and said she was never going to do it again. So, we don't even talk anymore at all.
Every single guy that I've come close with isn't my friend anymore because I wouldn't date them, and I guess they gave up. I don't date guys easily because I've seen what it does to my friends, and I'm just very.. complicated.
But anyways, 2 of my other close friends did the same thing Tiffany did.
There's so many more that it would take forever to list. I think about it way too often, but it really sucks when you know that that person doesn't give a care in the world if they're your friend or not.
But, I guess that's just the price with having friends? I just don't understand why it has to be that way. I really am a nice person, or at least people say I am.
Well anyways, I've been thinking about this because I found some old videos of Me, Tiffany, Jake, Emily, and my other friends Kammie, and Anna. There's a picture of Tiffany attacking me that makes me miss the old times. This was from like 7th grade.
Anyone else go through this?