Long story short she liked me and I liked her but I didn't know she liked me. I made her feel rejected by walking away during a conversation she started due to my own confusion. That was back in April. Then I learned she had been interested in May when my mom and her aunt (who are friends) had lunch and came to the topic of us. Apparently she'd really liked talking to me and thought we hit it off, but I walked away when she started a conversation with me asking if I was doing better (I had been sick), I accidentally walked away making her feel rejected in the first place. I apologized over text during June (summer break had begun) and she said I should have apologized in person but said it was alright.
We started talking again back in July as I wished her happy birthday. I wouldn't have done anything further but she texted the day after asking if we have any classes together. We texted for a few days after and it seemed like when we were first talking. But then I texted her once and she didn't reply, we haven't talked in over a month.
Now school has started and I haven't talked to her, a few times I've caught her looking at me and she seems to play with/stroke her hair a lot when I'm around. But otherwise we haven't talked or anything.
Honestly I'm crushed by my own stupidity for ruining this as it is my fault. I haven't been able to forgive myself since I learned what I'd done. I also just want to get this over with and know if she still has any interest but I don't know what to say or what to do.
What I'm wondering now is if I should apologize to her in person and also tell her how I feel?