How to stop feeling jealous/insecure in a relationship?

How can I stop feeling so jealous and insecure every time my boyfriend even mentions another girl or says they’re good looking? I just feel so threatened by any other vaguely good looking girl and just feel like he’s gonna find someone better every time he goes out anywhere. How do I stop these toxic thoughts?
How to stop feeling jealous/insecure in a relationship?
Post Opinion