How do I overcome Jealous in an open relationship

It's ok to feel like this, maybe you didn't know how hard it would be for you to be in an open relationship. But consent is something that need to be constantly present, if you're not feeling ok with it anymore you have the right to reconsider the way your relationship works. You can talk about it with your partner, let them know how you feel, make sure they know you're not blaming them since they had your consent, but with time you've found out it's too hard for you. Hiding these feelings can only make things worse, with time. Talking about it openly is hard, but it's the only way to make things better. You can find a different way to be together, something that works for both of you. And if nothing works, at least you'll know you've tried your best, and you'll both respect your own feelings without feeling forced to accept something that hurts you.

I completely understand! I struggled with that when my partner got a girlfriend (they've broken up now). Being I. A open relationship is such an emotional rollercoaster and can be tricky to navigate those emotions. I found it helped somewhat making romantic plans and one to one time where it's just myself and my partner.

@PatrickYoshida

I was also in an open relationship and I understand where you're coming from. The fear of losing the person you adore just because you're not okay with an open relationship is a really great challenge to overcome. We keep thinking maybe he'll change his mind and see your worth.
But honestly, the only one who benefits in the relationship is him.
It's difficult, I keep coming back whenever I'm halfway moving on. You would need a lot of practice and most of all ACCEPTANCE!