My parents relationship affects my own!! How do i fix it?

I grew up an only child for most of my childhood years. My parents would fight all the time and when it would get serious, my mom would just decide to separate and we would move for a few months. Now in relationships, I feel like the guy is gonna randomly disappear.

Anytime I leave my boyfriends house I feel like I’m never gonna see him again and it makes me extremely sad. It has also made me begin to completely stalk his social media. I check every single girl he follows with the fear that this girl will take him from me.

I’m not an insecure person but for some reason lately I have been. My boyfriend always tries to reassure that Instagram doesn’t matter and that he wouldn’t just get up and decide he isn’t into me anymore.

How can I change my habits???