HELP!!!! Need love advice

So long story short. There was this SUPER cute guy I went to school with and we were best friends and I began catching feelings like really fast but he made my heart flutter every time I saw him. But then he moved schools to an all boys school and I moved to an all girls school and we never see each other anymore it’s been 3 years and I still love him. Btw we kissed earlier on but only remained bffs. I don’t know if it’s because If my periods or anything else. I don’t know what to do and lately I’ve been feeling depressed because I miss him sooooo much. What do I do?!? I don’t have his number or anything!! Please help!