I made a mistake and now I feel empty

Hello. I feel like I had made a mistake and im now poundering on the what ifs. For context, Im a poly student and I had a general module this year.

On the first day, I met this girl in my group. I instantly liked her. But shes not so the outgoing type and if she is, shes not talking to me. I have a feeling shes always singling me out for some reason.

But there are occasions, where she shows some interests such as copying my actions, for example, I like to hug my bag in class, she does it too. Wearing the same shoe as me. I’ve been wearing it since the first day of the module.

She has a few times sparked conversations with me such as apologising for not coming to team meetings over zoom cos she didn’t see the message, and asking me things about the project, and wanted me to demonstrate how she should present it.

On presentation day, shes also the only one who remembered that I had a paper prior and asked me about it. I really should have just asked her out at that moment.

I feel like she has some interest? and tried to make some moves. But being the coward and introvert that is scared of rejection. I did not confess/ even ask her out. Which I really wanted to do on the last day of our project.

Now the project has ended and realistically, I do not have any reason to meet/talk to her anymore. I’m now poundering what I have done. Why didn’t I take the chance? so what if I get rejected? I’m not gonna see her again. And now I made a choice I will regret.

I really do not know what to do. I just feel really empty and I really miss her. I’m hoping for a miracle in which she asks me out but that’s probably not gonna happen and me asking out of the blue may put me in a position where I act and look like a creep.

What should I do? should I put on a thick skin and message her out of the blue or just let her go?

Thanks for reading up till now. Please leave any advice below.😕