How to reconnect with an old friend (when it’s your fault the friendship ended)??

In high school (about 7 years ago) me and this person were extremely good friends, to the point we considered each other family. We played football together, his dad was the football coach, our parents grew up together, and either I was constantly at his house or he was at mine. We both grew up in single parent households, and with us being together so often, my mom took on a mother figure role for him and his dad took on a father figure role for me. I say all this to really explain how close we were, we considered ourselves brothers.
Then during the last year or two of high school, I messed it all up. Long story short, I got in a relationship and completely pushed my friend to the side. I stopped talking to him, stopped hanging out with him, and basically just ignored him. The relationship was extremely toxic and she was basically the one leading me to do this (I still take full responsibility for what I did and am not putting all the blame on her). Of course this high school relationship didn’t last, and I found myself without my friend/brother. I wanted to fix this so bad but was too ashamed to reach out. One day our paths randomly crossed and I apologized for what I did. We then hung out once or twice but ultimately stopped talking and hanging out cause we were both heading off to college. Now we’re finished with college and I really want to reconnect, but I have no idea how. I still feel ashamed for what I did all those years ago, even though I apologized and was forgiven. Ive tried searching him up but he never was big on social media so that was a dead end. I have a phone number for him, but I’m not sure it’s still his number. And even if it still is his number I have no idea what to even say.