Would I be a stalker if I messaged him on FB?

So I met this guy on Tinder and we instantly hit it off. Great chemistry, great convo, he had a great personality...needless to say he definitely has me interested. We decided to meet up today but that night after I messaged him back, all of our messages vanished. I couldn't find him in any of my matches. I assumed either he or I accidentally unmatched from each other(I've done that before). 
 I don't know whether to assume he just wasn't interested anymore or if it truely was an accident on one of our behaves. I tried finding him again and I swiped through so many people I ran out of profiles. I did however find him on FB. Would it be taking it too far if I were to message him on FB? I don't want to seem crazy or stalkerish. Should I just leave it alone or would it be okay to message him on there?