After blocking me for a year and not speaking to me, my favorite person came back, and it's ruining my life. They aren't my partner but are of the “opposite sex,” and it's causing a lot of confusion.

Me and my favorite person argued yesterday, and it derailed my whole day, and all i could think about was how to fix it. How to make it better. What makes it worse is he turns himself into the victim within the argument by saying things like, “this is why I don't tell people anything,” “im misunderstood by everyone,” so even if it's about my feelings, he just uses those tactics. I don't know if they are tactics or feelings. It's really confusing, and im so tired of this. 

What do you do to make a person stop being your favorite person?