What can I do about Jealousy?

I think I have a problem with Jealousy.

When I know a girl, that I wanted to date or was a crush... and I see her talking to another guy I lose my stuff.

A couple examples:

I saw my crush flirting, laughing and sitting next to another guy... and I got really angry, I was angry for the rest of the day, and I put all my anger into my work... I really wanted to punch that guy. I really like her so much.

This one is weird, I met a girl on Tinder, although we never clicked and went out... we had each others Facebook and just became Friends... I don't even like her, care about dating her... but I saw her post a picture with another guy and I got angry. ( Which is strange because I don't even care about this girl)

How and Why do I get Jealous? What can I do about this? Is this normal?

What can I do about Jealousy?
Add Opinion