Am I in the wrong in this situation?

[Akira]

I'm really sorry for the long wall of text, but please read all of it and give me advice. It's pretty serious to me and I need to help in deciding what to do.

So I have this friend that I've known since 9th grade and we've been very good friends. I'm a guy and my friend is a girl, if that matters. I'll call my friend T. I should also state that we both have another really good friend (girl) from high school. I'll call her A. We all now go to the same college. HOWEVER, while we were such good friends in high school, I feel like me and T are drifting apart in college. I have some reasons why I think this.

1. It's weird because, all in high school, there was this guy in our senior class that would always tease T, sometimes in a good or a bad way. They were friends on and off a lot. All through high school, T would tell me and A about her problems with this kid. That was the bulk of our conversation. We would talk about school/music/tv etc. as well but not nearly as much. Now that that kid isn't in our college, I'm finding that our interests aren't as similar as I thought. So conversation has been dull, unless she brings up that kid again (which she does at times still...)

2. T has a roommate that she's known for 13 years and a friend that she's known for a shorter year span, but longer than knowing me. T and her roommate are attached to the hip. When T asks me and A to hang out with her, her roommate is always there. Me and her roommate get along, but we are not friends. Definitely acquaintances. Every time the four of us hang out, she never talks to me like she used to. She even talks to A more than me but she talks to her roommate MUCH more. So I always ask myself, "Why did I come?". I'm just there with my phone talking to A while T talks to her roommate.

3. I think I've matured since I started college. Back in high school, we used to talk about random kids. Like if there was a girl who was slutty, we would talk about her and make jokes and what not. As of now, that doesn't really humor me anymore. Another point is that T is very sarcastic. So anything I say, she will answer with a sarcastic response to make me look stupid. Then she and her roommate would hysterically. This has been the main thing that bugs me out about her. I'm sarcastic as well, but apparently I'm the bad guy if I try to respond like that.

4. It seems like she doesn't want to hang out anymore. Every break we get, like Christmas break, we usually hang out outside of school at the movies or a restaurant with another good friend of ours from high school. Call her AD. This past Christmas break, she never asked me if I wanted to hang out. Instead, those T and AD hung out together with another guy friend from our high school. She knows that I can drive and she knew that I was within the distance of the restaurant they went to. Yet she never asked me or A to go with them. I know this because she put a picture of all of them together on facebook.

So these are my reasons why I think we're drifting apart. Me and A are still good friends and hang out with each other a lot more. I recently talked to T and she was telling me about how I'm such a stranger now because I don't contact her anymore. She says that I have her phone number and facebook but wonders why I don't talk to her. I just shrugged it off because she's also one to start arguments. I knew an argument would ensue if I told her my reasons, but I really wasn't in the mood for that.
So am I in the wrong for not making more of an effort to contact her? She always texts me first, but she never had a problem with it before. I don't text her because she's been putting me off lately. It's like she doesn't make an effort as well. Any advice please?