Something changed

We barely communicate anymore. Some days we don't even text at all. He used to send a good morning text everyday now I barely get that. When we text he takes forever respond and before we used to talk all day now we barely do. I really want to just ask him what happened but i guess I don't want to come across as if I care more. I see him post things on snap chat, looks like he's living his life perfectly fine. I'm just over here sad constantly thinking about him and I don't know if he's thinking about me. Should I ask him what's up or just let it be? I really care for him.