Should I try explaining how I feel to this person?

OK, I am a senior in high school about to go to college. I befriended this girl and said I was gay in October. We spoke mostly on facebook and by text message. In October-December, we spoke mostly online and phone with text but occasionally saw each other at school and said hi and spoke. She commented on lots of my facebook and instagram posts. I liked her a lot and I told her some secrets and I even offered to bake her a cake for getting into college. She said she'll always be there for me. However, this month, I sent 5 text messages. 2 were responded to very late with barley nothing, and 3 were not even responded to. I saw her at schools numerous times but she never said hi, and if I said hi and tried to have a conversation, she would have it but act like she didn't know me that well. Today I saw her in a transparent room where I was sitting all by myself and she was about to come in but when she saw me she looked me in the eye but didn't wave, turned the opposite direction and went to sit with another group of people that it looked like she had maybe been trying to avoid by going into the room I was in. Then, in a class I sit near her in where she barley spoke with me for the whole month, it was just me her and another girl. I spoke to the other girl and the original girl I texted said nothing to me when it was just the 3 of us, and nothing when in class where I sit right next to her. I am not sure if I should talk to her. Maybe she is mad but the way this is being done seems inappropriate. I don't know if I am thinking too deeply into this but I feel kind of used and I said things that were personal to me and I feel like I should be treated better. Should I speak with this person and explain what I am thinking? We are almost leaving high school and a fake relationship doesn't matter to me. Thanks for helping!