Real Love?

I really like my sisters friend and she really likes me.We get on so well together and almost *everyone* knows how much we like eachother…but I’ve been so rude to her recently and such an idiot *with other girls* that she’s kind of fed up with me and doesn’t believe I like her..but I really like her a lot.She is gay but that doesn’t matter even though she thinks it does….and I don’t know what to do or say to convince her that I’m not ‘messing’ anymore and I really want us to be as close as we used to be..because I genuinely like her a lot.What do I do?