Best Friend?

Is it ok if I can't pinpoint who my best friend is?

I know I am being overly emotional right now or I could be starting my period soon...but I've just hit a low point today and I need to rant.

All the questions that ask "Who is your best friend?" I have to seriously think about who it is at that moment.
There are two people who I want to call my best friend.

The first is my friend that I've known since 4th grade and we used to be inseparable in high school. She was like my shadow and we had our own little world at times, but recently I don't feel that close to her anymore. It was a slow process with me going away to college and her interests and fandoms diverging from mine. We used to be so in sync and she is who I credit my love for Asian cultures to because she introduced me to some anime and then we both got into Jpop, some Kpop, and dramas. But somewhere along the way she got away from all that. I tried to keep up with her by watching Glee with her over Skype and binge watching episodes I had missed when I would go home. I also fell in love with Starkid because of her and went to the tour stops in Texas with her. But now she's big into American mainstream music, shows and topics and a big LBGTQ activist. I'm not saying I'm against those, but they're not my passions. I'm not saying that we can't be best friends if we don't have the same passions, but I really want to connect better.

The person that I share feelings with and we share fandoms/passions, I have not known for very long. I feel like it took us such a short time to get so close, but I can't be her best friend because I'm late in the game. Her other close friends that have been around longer than me come first in her mind, which is totally understandable. I know it isn't fair to say things like this, but that's how I feel sometimes. I know we're real close, but she's like me and has many friends that she loves and protects. I just want to be first in someone's mind. Two of her other close friends came and got her last night to hang out and I didn't know until she told me earlier. I thought we were all close, but in my mind I can't get on their level because I'm still sorta new to the group. Up until I became friends with them, I never felt like I had a "squad" or"clique" to belong to in college. But even with them I still feel like I don't belong at times.

I guess I just want to have a really strong connection with someone where we are totally in sync with our thoughts and passions.

Not even can my boyfriend be called my best friend. We really don't have all that much in common actually, but it still works I guess. I don't want to try and push my passions onto him, but I want to be able to connect better with him. I see couples all the time saying that they are married to their best friend and I want that.

This is the only time I feel selfish for attention.

My whole life I have just been floating from friend group to friend group. I have made friends everywhere, some very very close friendships, but I don't think I've ever found someone that connects with me completely or where I felt like I completely belong. Most of my Christian friends don't share other passions with me and most of the people I want to be close to that have the same interests don't share my religious beliefs.

This is the only time I hate myself, when I'm selfish for friendship because I wasn't invited somewhere.
But...this will all not matter soon, because my rare moment of depression is soon over and I will go back to my happy and mostly indifferent self with plenty of friends and people that care about me.