How to get over puppy love

My ex broke up with me. We’ve been together for almost a year. It was so bad that I had horrible panic attacks for two days straight. He knew he meant the world to me. He knew I was vulnerable with him. He knew I considered him my best friend. And he broke up with me anyways, un-phased by the whole thing. I knew he was inconsiderate of people’s feelings, but to do it to me. I’ve learned an important lesson, but I wanted to be able to part ways in a different manner. he just decided that day was the day. It’s been a couple of weeks since the breakup the great thing is I’m starting college and I’m excited about it. It’s just I’m getting tired about thinking about him 24/7. To the point where I don’t even want to be alone with my thoughts anymore. Does anyone know how to deal with this? How to get over someone?