I'm missing from his online life?

My boyfriend and I have been together for a long time. And yes, I know that sometimes social media can get in the way of a relationship and I try not to look too deep into his online life but I'm absolutely nowhere in that life. He doesn't post pictures of me, he doesn't comment about me. He's not really the type of person that would post a lot of things but he's always browsing online. He's always on his phone looking at Facebook or Instagram so much so that I have to ask him to put it away. He does post creative art pictures or music but sometimes he posts people like his mom, sister, and brother but not me, his girlfriend. So why do I feel so kind of way about this? I post pictures of us all the time, I tag him when we go out, but he never likes them. I even posted an anniversary picture, tagged him and he didn't even know even though he's always online. Someone please tell me I'm thinking too hard about this and should just leave it be.