Did I mess up with her and if so, where?
Back in October, I started talking to a girl in my class (we are seniors). At first it was just little texts here and there but eventually it turned into a little more. Then after a little longer, it escalated further. And by December, it seemed like it was going somewhere. We were talking ALL day everyday. We were both being super flirty and we even got into a few really deep and personal conversations. She would "pretend" to fall asleep on me so I would send her some sort of goodnight text and then in the morning she would always send me a good morning text and would try and continue the conversation from the previous night. We hung out a few times and they eventually turned into dates. And overall, we both seemed to be getting really comfortable with each other. We never discussed officially dating or anything though. It seemed like we were both just going with the flow of things.
But one day, I was talking with her and her mom. After I left, she texted me and I said something about her mom. She responds with "Well we are basically the same person". Trying to be flirty, I replied by saying "Well I'm sure I'll like her then" She responds by saying "Does that mean you like me?". Kinda confused because I felt I had made it pretty obvious that I did, I decided to just be completely open with her. I told her that I did like her a lot and had developed feelings for her. Like an hour later she responds telling me she likes me too but was not looking for anything serious at the time and that she was currently "playing it safe". She ends the conversation though with "I hope you know I am not crossing out the future between us." Things did not get weird or anything but after about a month she, for whatever reason, decided to start being really distant with me and ignoring me. After about three days, I just said screw it and decided to stop chasing so that I would not seem super clingy and annoying. It's been four months, and we are still friends and all, but we have really drifted in comparison to what it was before. And on top of that, she is now with another guy. I do not know where I messed up or if she messed up or what. Should I not have opened up to her? Was she not being honest when she said she liked me too and that she was not crossing out the future? I am just really confused on what happened to make her suddenly just shut me out after getting all close with me and then friend zone me.