Can I be straight?

So, i'm a 21 yo guy who fall for another guy before, like having a crush on him. He flirt with me, I flirt with him, but in the end he got a girlfriend. And then I found this girl, she's so fun. She makes my day more interesting, like I keep on waiting for her text, but in the end I'm the one who texted her though. It start from when I knew about my crush having a girlfriend. I started to like her name that I never called before, I keep on calling her name over and over again. And somehow, everytime she talked about another guy, it makes me feels dissappointed. Or am I jealous?
She makes me smile for no reasons, and almost all of my family and friends know about her now. I want to be always by her side when she needs someone. Am I in love with her? Can I be straight? Cause I don't even think about my crush anymore, all that I know is my mind is full of her. Well not all of it, my university life still on my mind （￣へ￣）