I know this is ridiculous but I really could use some advice on how to deal with this.

I’ve been with my boyfriend for about 8 months now and he’s literally perfect. There’s no issue except I can’t help but get pissed at even the thought of his ex. I have exes too but he never has an issue because there is no reason for an issue because they are completely out of my life and I WISH I could see things like that for him. I know he’s over her because they broke up 3 years ago but I can’t help but feel insecure. They dated for 3 years, moved in together and got matching king & queen tattoos. They traveled the world together and his family loved her and took her on their vacations and they still occasionally bring her up when reminiscing on their past times. His mom is still friends with her on Facebook. I love his family but I can’t help but feel slight anger about this, I feel like I’m still seen as temporary compared to a girl in the past (even though it’s not really like that). I know it’s all in my head but I could really use some advice on how to not get insecure/jealous or feel like a replacement. I mean he traveled everywhere with her and he did EVERYTHING with her and now I don’t even want to be adventurous with him sometimes because I just feel like it’s not going to be as good as the first time. I don’t want to take my jealously out on him because he does nothing wrong and has not spoken to her since they broke up. Please help!