i miss her too much

i miss her so much it's fucking painful. i know that we're never gonna talk again, even just as friends because i just fucked it up so badly. we never even dated, and im leaving my current school this year in a few months, so i know i'm never gonna see her again. for context, i'm a teenage girl. i've been in love with this other girl in my year group since 2021, and even when our friendship ended i couldnt stop missing and thinking about her. TW for suicide mention, but i would fantasise about if she would miss me if i passed away (sometimes i still do, but rarely), i dream about the what-ifs. what if we never fell out? what if i had just asked her out instead of being a stupid coward? what if we had a future together? the realisation has struck that i'm never going to find another maria. there's only one of her, who i'll never see again in just a few month's time. we had a small interaction the other week, where we had this extremely annoying visitor come and speak to us about STEM. in our history class afterward, before our teacher came, she was talking about how annoying said speaker was. i decided to briefly join the conversation with a "he's the definition of 'i hate men'", which got a small laugh out of her. that was when i realised that i would miss those beautiful sparkling green eyes and that sweet smile. im gonna miss my sweet girl so much. how do i cope with this?