This girl inconsistently acts like she hates me when I think she has a crush on me?

confusedguy20
Sounds stupid I know, but yeah...she goes to my college.

One minute she acts very talkative and will talk to me and is able to look me in the eye and acts very interested. One time she couldn't stop touching me during the conversation.

Next minute she's cold and aloof, talks in a deeper tone, gives one word answers, can't make eye contact, and acts really awkward and kinda mumbles. She'll either ignore me or just say hi in a really cold way, though a lot of times I've noticed that a big smile comes up on her face after she passes by me when she's like that.

Sometimes she acts straight up irritated at me for no reason, like I'm bothering her. She's even kinda snapped at me a few times...and last semester she FLIPPED on me when I was just trying to look out for her, and everyone that knows about it thinks its very odd she got mad and doesn't understand why she did.

Then sometimes she's EXTREMELY nervous around me, acts very awkward and blushes alot, basically makes it really obvious that she likes me. I've noticed a few times in the past that her friends giggled at her when they say me walk by, and she would blush and look down and smile.

After awhile I got so confused by her behavior that it shook my confidence pretty bad and I really started to hesitate asking her out. Eventually she started dating this older guy from some other school, and they've been going out for a little more than half a year now. And she still acts exactly the same, in fact it was after that when she really flipped out on me that one time.

And she's always been staring at me a lot ever since the first day I met her. This has been going on for like two years now, even though she's had a boyfriend for the past 7 months almost...

Does she like me or am I crazy? Should I confront her about this? It's been really awkward pretty far this semester.

Updates
+1 y
When we met in high school senior year, she had a boyfriend and told me she would totally go out with me if she wasn't in a long serious relationship. We didn't see much of each other back then though, she was only in my driving class. Not even long enough for her to start acting like the way she does now.
This girl inconsistently acts like she hates me when I think she has a crush on me?
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