Do i have a right to feel this way?

He says I’m insecure but he had his ex as his homescreen, told another girl he missed her and was talking to his ex off of someone else’s phone. He’d talk to other people but not me ... I’d get jealous sometimes but the reasons listed above are why...he flirts with everyone and these females don’t care...he told me they’d been like “here’s my number if you want to f*** and only that” He tries to say “it’s all in your head” yeah okay dude. I know I get jealous and I’m sorry, I mean I’m definitely not secure in what we had going on based off what you did.....was I wrong to feel jealous & upset? Am I insecure? I’m so sad...I really wanted you but you wanted me AND other females... 😞

Edit- We are done & i’m just sad