Do you ever feel this way?

I was just wondering if anyone else ever felt this way and how they knew if they were right or just self conscious? 

I'm concerned my boyfriend is just in this relationship because he doesn't want to be lonely, he wants someone to have sex with and cuddle with, and I'm a placeholder until he finds someone better. We have been together for a year now. I feel like he's never interested in what I have to say, and he doesn't put effort into this relationship to show me that I'm special to him. I don't think he loves me, I think he loves being in a relationship. He's always happy with our relationship, even when I think that things are shitty, and I think it because this isn't a permanent thing for him. It serves its purpose for now, it takes the edge off the pressures of our high intensity career.