Boy problems

I have liked this boy for 6 years, me and him were friends 6 years ago, that was until he got popular and I realized I was ugly. He is now the most popular boy in the grade and I recently glowed up over the summer, but none of this really relates to the situation. So I added him on Snapchat a two months ago, and he added me back, I was happy then and I was having a great time with life. But then one day out of the blue he unadded me when I added something to my story, it wasn’t anything bad, but I think he just got tired of me. Although he was checking my location on snapmaps multiple times, and I tried to talk to him by sending streaks but he just left me on open. I tried getting his attention once by typing then leaving but he didn’t even notice. I really like this boy for many reasons, but he barely knows I exist. But it doesn’t end there, when he unadded me a month after he added me I became sad and I unadded him and then added him again as if it was a accident. Well I also have been catching him looking at me multiple times in a day, but then I got added to a groupchat. It was a groupchat of one of my classes, no one really wanted me and my friends there, so most of the popular kids left. Until it was a dozen kids left and him, I knew he was gonna leave but when it happened I cried. Every bit of hope I had left just went. And then I cried for 5 hours straight and now I don’t know what to do. I tried getting over him but nothing is working. Any advice?