Relationship problem

I am currently in a relationship where I'm really struggling to work out whats going on, and I think it might be falling apart.

Around February, I went on a date with a girl who I liked. The date went well, and I think we both left it excited to go on another, at least thats what she told me. We tried scheduling another one, however this was at a busy time and we had exams coming up, so we thought it best to wait until after.

However, that time came along and she again told me she was too busy - not that big a deal, but it kept happening. Weekend after weekend she would bail on me, (all while hanging out with friends regularly) and I started to get a little annoyed, so I asked her about it, and she explained to me that with school work and revising for our upcoming GCSES, she was too busy and told me that in the Easter she would probably be available, but that she definitely still wanted to talk. It's also worth noting that at this point, we were messaging regularly and the conversations were interesting.

However slightly before the time I confronted her, she stopped sending snaps to me entirely and her messages became irregular, and I started to worry. Easter came by and she cancelled again, this time postponing any date or anything until after our GCSEs. I was naturally fairly annoyed but understood that it was a stressful time and decided to wait for her. But gradually over Easter her messages became even more irregular, I'm talking often over a day between messages. I was annoyed, and so when we had our Dofe practice expedition last weekend, I gave her the cold shoulder. By the end of the expedition I felt bad, but thought that if she didn't want to talk, she wouldn't message me after I ignored her in person for 2 days. But then she did.

And that brings me to the past week. We sit next to eachother in one of our classes, and during that class she was more conversational than shes been since we first started talking. It was a really nice surprise, and I felt really good about it, and she then started texting me way more than she had during Easter. But the conversations were off. It was never about anything above surface level conversations you might have with a stranger, she still never snapped me even when I snapped her. And, although this might sound trivial, she stopped sending "x"'s after her messages. This was something she and I had done with eachother even through Easter when she was ignoring me, and it made me start to worry if she just thought of me as a friend now. Then on Thursday I heard that one of her male friends that she new pretty well seemed to think she was making moves on him. That really ****ed me off, needless to say, and that combined with everything else left me completely unsure of what to say to her. So I just didnt say anything and left her on delivered for a while. I thought If she was interested in me, she would follow it up.

During that day, the other guy messaged me and told me he doesn't like her, and she messaged me asking if everything was okay. Even though I should be happy about both of those things, I'm just not? I told her everything was fine and we talked for a while, but still no "x"'s, snaps, or anything really and eventually the conversation drifted off towards more trivial stuff. I don't know what to think. Am I being selfish, unempathetic or just an idiot? What do I do now? Is she indicating that she just wants to be friends? Am I in the wrong? Should I wait it out still? I have too many questions.