I think i'm going to give up selling the item. Now, I have to close 2 sale actions. What should I do guys?

One way to avoid this issue is to accept PayPal only and set up the listing so that immediate payment is required. That way, the item isn't sold at all unless and until it actually gets paid for.

It can still be subject to scams, but if you send the item fully registered and insured, you should be able to protect yourself from them.