How do you lose feelings for someone you really like a lot?
So, I met this guy 10 months ago, through a friend of mine, and we hung out every day for 3 months, besides on the weekends and the days he couldn't hang out, til late May, within a month of hanging out with him, I developed feelings for him but I didn't tell him til after 6 months of knowing him. Then I didn't see him for 4 months after that. He has a girlfriend now, and he isn't really the same as I knew him, yet, I still have feelings for him. And well, the way I see it, I have no chance with him whatsoever, and well I don't want to have feelings for him anymore so how do I lose them?
p.s he sees me as his sister, and well i want to lose these feelings for him so when I hear about his relationship with his girlfriend, I won't be hurt at all.