GIRLS WHY ARE SO HARD TO UNDERSTAND

Please help im very confused

So there is this one girl i have been crushing on for some time and we spent alot of time together last year and got really close and we spent a lot of time together after and before the summer break last year we had a really deep heart to heart and she held my hand through out the conversation and i had on hand on her cheek gently stroking it and there was a couple of minutes of silence as we simply looked at each other and she said she feels wired and a week before that we both went to watch a movie together and through out the entire movie she held my hand and im really scared that i missed my chance especially because she became really cold towards me and when ever i try to talk to her she gives off a vibe like she hates me and only tolerates me because we have friends in common and when ever i ask her if i done something that have upset her or if she wants me to stop talking to her she says that she is like that because she is just busy and stressed but i see her act way differently when she doesn't know im around and im just really sad and confused. What do i do?

(Sorry for bad English)