Yes. Invoices sent to you mean that you are paying him, but he made it look like he sent money to you aka scam
If you accepted the invoice , yes you got scammed. If you talk with Paypal support , I guess you may get your money back, but I am not sure about it. There are many people knowing about Paypal disputes and scams here in MPGH, so lets wait for someone more experienced to answer. I just suggest to stay calm (if you can), I am thinking positive about your position. Good luck mate!