How do I stop projecting my insecurities?

I feel like I tend to get insecure whenever my partner comments on another womans looks (e.g. that celebrity is good looking/ attractive) or spends time with female friends (1 on 1 or in group settings but they’re all women). My feelings get hurt or I get jealous. Then I’ll start comparing myself and come to the conclusion that I’m not good enough and they’re better than me? And I’ll question our relationship. How do I stop this insecure thinking? Any advice is appreciated.