How do you deal with Jealousy?

How do you deal with Jealousy? I've been jealous of this one certain person ( who I won't mention ), she's not.. that kind of a bad person, but someone who affected me for the past 5 years, I don't really know much of this person, but she did say affective words to me. Though I was a kid who confronted her about something, she actually said hurtful words to a 10 year old, she never knew that child could actually envy and be jealous of her and sometimes smiles when she's confronted for wrong doings. I don't think she's a bad person but she affected me badly to the point I wake up worrying if she'd say words to me. I love something and I'm good at it, and somehow the motivation dissapeared ever since I knew her because she was way better at it. I don't really know how to describe this hatred and non-hatred about her. I refuse to talk to her again. But I don't know why I still bother to think about her. I need help to forget about her but I keep having this horrible habit of checking her social media ( just one account ). I've been like this all because of jealousy.