Should I apologise to her? Or leave her alone? Please help!?

Well she probably did feel awkward and when some girls only see a guy as a friend and the guy declares to her they feel really awkward. I could tell you didn't mean to do that. I honestly believe you should talk to her but I mean like after cl right after cl ends when the cl is heading out the doors go up her and like literally stop her and tell her you want to talk... ask her if she's made at you and tell her you that you didn't really mean to make it awkward like you said it on here once your done saying that to her just leave her and that will have her thinking if she really wants to talk to you she will after and if not she won't but at least you would have let her known how you felt and what your true intentions were. I really mean stop her and talk to her a couple of minutes of her time won't hurt her or you. Good Luck!