How do you get over a breakup

I don’t know if anyone is going to care or even read this but I’m 13 years old so you might think I’m overreacting or something but this just seems like a lot on my plate rn and I could really use some help. So I’ve had two “relationships” in the past where we mostly communicated by text and it didn’t really bother me when they ended but, this one was different. This one felt real. He was in 8th grade when I was in 7th (our school goes from k-8) but we officially met during the play (guys and dolls) when he was cast as my fiancée(Nathan and Adelaide are the characters names if you wanted to know). I never really noticed him before although we had been going to school together for a couple years because the other classes don’t really talk. We talked all through play rehearsals and the show and texted each other almost every night. After the play he asked me if I would go out with him and I obviously said yes. We dated for 5 months and 23 days and went on multiple dates where I felt like the happiest girl alive but, I always thought about what would happen when he went off to high school and I was still a little 8th grader. I thought it would last and we would have a chance but the first day I saw him during the summer we went to a carnival and at the end right before he was about to leave he said “I don’t know how to put this but um I think I think you should date someone who likes you as much as you like me, I think you deserve to be with someone who 100% likes you, I’m sorry”. I spent all of the week before thinking how I was going to tell him I loved him and he shattered my heart to pieces. I never told anyone what I’m about to put on here, not my best friends nor family but the day I he started texting me I was having ta really hard day, I was about to do something rly stupid, I had it all planned out and I was ready. But then he texted me I was so happy to have someone new to talk to and get my mind of things then he said one thing that upset me and I blew up at him, he thought I hated him in the beginning on that day and it was easier to just let him think that but the truth is he saved my life and now I’m all alone Brocken inside and he’s gone. No one in my life knows the truth and everyone thinks I’m ok now after 2 days but I’m not and I can’t let them know that. Please help me if you read this I would be so grateful. Thank you❤️