Well friendo, sorry to hear about your bitcoin balance troubles. But I think we need a few more details before we can make an assessment of why your Bitcoin balance is not showing up as it should be. The first question that comes to mind would be: which wallet are you using? It might just be an user interface problem, most likely. In the worst case scenario you might have gotten hacked but thats the least likely thing to have happened, if you were careful with your passwords/keys/seed phrases.

Depending on the wallet, you might have to wait a while and refresh.