I don't even talk to this person in real life but does she like me?

I'm really confused about this girl at school I really like. I started liking her more than a year ago when I first moved to college. At the time, I liked another girl, but I kept noticing her looking at me in classes. We are in 5 lessons together. I eventually fell in love with her during a biology lesson when her friend turned round to ask for something, and she turned round as well. I immediately locked eyes with her and it lasted for at least 20 seconds until her friend turned round again. It felt like time had stopped around us, it was incredible.
I am now staring at her whenever I get the chance! I cannot help it. I often look at her and catch her looking at me already. However, sometimes it doesn't happen a lot. It varies each day. But when we do make eye contact, it lasts quite a while. I've never talked to her in person except for the few times when I gathered the courage and apologized for staring, which she always just replied with, "It's fine." It was always an abrupt ending. Oh, and the time we were in the same group for a presentation and I was the leader. The conversations then were also very abrupt. At lunch, she always sits on the end of table, facing directly in front of the entrance to the dining hall, so whenever I walked in, it was immediate eye contact. It is like she is deliberately waiting for me.
After a half a year of this, I finally had enough of it and felt so bad for staring. I must have made her feel really uncomfortable. I gathered even more courage after sports day (a lot of eye contact that day since she sat out and watched the activity I was playing..), I confessed to her via Facebook. My confession was really detailed about my feelings. It really did not turn out great since she never used Facebook so she didn't see it. I waited a few weeks until I broke and confessed again via letter. This time it was a lot simpler and I told her I thought she was cute and I cared a lot about her in this letter. I gave it to at the end of the day, but never got a reply. I never expected one, but she still looks at me.
We broke up for the summer holidays shortly after that, and within the first two days, I checked Facebook like I do regularly to see if she had seen the confession. To my surprise, she had about a few hours ago, but she didn't reply. I was freaking out to my friend (I was round his house at the time), and managed to accidentally send an emoji to her. Twice. I sent a message saying sorry about that, and after a few minutes, followed it up with, "Why do you not reply to my messages?". I know that sounded moody but it worked.
I got a reply that night at 7 so she had obviously gone on Facebook to read it again. I mean, she doesn't get notified when I message her. She apologized and used the excuse that she had bad signal. She said she didn't know what to say to my confession. I replied saying it's okay, and asked her why she had bad signal. She told me she was at a Doctor Who event in Wales. I asked her if I could ask her a few questions about herself and she replied sure. That night, we talked about ourselves until 10. She did take several minutes to reply, but it was the best night. At the end of the conversation, she said "Talk to you later", and sure enough, throughout the summer holidays we talked on most days. I was always the one to start the conversation and she did take hours, sometimes 1 or 2 days to reply however.
The week before we went back to school, she stopped going on Facebook and school soon arrived. There was still eye contact but it was clear she was avoiding me! I felt so sad. I couldn't function properly. I messaged her saying something along the lines of how I understand she doesn't want to talk anymore but it makes feel sad. It wasn't until the first Thursday back that she replied. She apologized and told me she doesn't get notifications and still wanted to talk. She asked me how I was. After that, we carried on talking on Facebook and it felt like we had gotten a lot closer. She sent me pictures of her coursework for graphics and a cake she baked, etc. She never sent me pictures before! I asked her why she liked Doctor who and she spent more than ten minutes writing out a massive reply to me. It was amazing. The night Doctor who premiered it's first episode of it's ninth season, she sent me pictures of anything that displayed the time in her house, and she was freaking out typing random letters. It was so weird but cute. After the doctor who episodes each week, she would nearly always send me a huge paragraph freaking out about what happened and how she felt. One night, she messaged me on Instagram (I asked for her account) because her phone ran out of charge and it made me feel good knowing she wants and is comfortable enough to show this side of her...
I have seen her like some posts about being bisexual on Instagram so that's given me hope.She regularly starts conversations with me now so she clearly wants to talk! I can also see when she is last active on messenger so I can see when she checks for my replies (I asked her if she talks to anyone else on FB and she said not really) and it is quite often since sometimes I don't reply for hours even though I've read her message.The eye contact during school is way too much to count now. I mean, she sometimes stands or sits right in front of me on purpose, and glances when she talks to her friends. Even my friends have caught her regularly turning round to look at me during lessons.
Recently, she had to sit on the same table as me with a few other people in physics on day. I was left out of the conversation so I was on my phone and suddenly she messaged me! I could see she was on her iPod but she was avoiding eye contact. Why couldn't she have just talked to me?

I just want to hear some opinions on whether anyone thinks she likes me or am I just reading too much into this please! I mean, I'm really not the best looking person and not the most fun to talk to! Advice is also welcome. Sorry for the long post, I missed out quite a lot of stuff if you can believe that. :lol: