Why I still love him even though he hurt me so much?

I know this guy for so long like 10 years and our relationship up n down. He kinda rude guy who likes yelling with bad words when he was angry, very often he gave me silent treatment, very slow reply my messages, sometimes sweet but in another time he treat me so bad. I asked him if probably he has mood swing problem but he didn't answer it n just went away.
After everything that he did to me i still love him. I tried so hard to forget him but he stuck on my mind. Its unussual feelings for me. What should i do?
Why I still love him even though he hurt me so much?
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