I really like this guy but it's complicated.......

I used to be best friends with his sister. He would hang around with us and he was really cool and sweet. He knew that I liked him and one day he told me he liked me too. A week later me and his sister had a big fight. I haven't spoken to either in two years, but I'm still crazy about him. I seen him the other day and i couldn't breath. It made me realise even more how much I miss him. I know it sounds sad but I've never felt this way about someone before.

I could really do with your advice and would really appreciate it.