Hi Belle!
Stop blaming yourself or even your “ego” for that kind of stuff. You are not the victim of your ego! We are humans, and our reward system is by default addicted to attention. The only thing you can do is to accept that it is an addiction and treat it like that. You will not make that feeling stop. But you can try and “redirect” it like Inky said, find something healthier to replace it and to give you a feeling of reward. (I like to think that the “ego” is a bunch of apes, and you don’t want them to take control over you, and mindfulness is good and all, but sometimes it’s ok to satisfy their needs and give them some carots.)

BUT: Don’t give them sugar! Don’t feed the addiction! So firstly: Block him on social media!!! Unfollow him on instagram! NOW! If your profile is public, kindly ask him not to interact so you can get closure. (But I’m sure there must be a way to block users on insta too…)
Secondly: You can’t just “let go of ego” and make your feelings go away. You can be mindful about it, but a breakup is still painful! A month is not a very long time. It will take more time to heal. But it will happen. You will find others whose attention makes you feel better, and in a healthier way. Make space in your life for them. You are on the right track!

Love, kath