Just a few things to add to all the fantastic information that the countess has given you.

Apart from changing your details, passwords etc :

Be sure to run all your spyware, keylogging and virus protection.

The scammer will give all your information to other scammers.

This information will be stored, to use at a later date.

The next scam may  actually come from a genuine eBay user ID, but the account may have been hijacked by a scammer.

The next scam may not involve apple gift cards.

It may say your payment's on hold  and will be released when  you've given them a tracking number.

DO NOT confuse this with eBay's payment hold for new sellers.

As recommended by the countess, I also agree that you should remove  all your listings until you know more about selling on eBay.

Then start with selling cheap items.  Start afresh.

You haven't sold anything for a long time  so  eBay will treat you as a new seller.

Have you actually registered to sell and signed up for managed payments ?

https://www.ebay.com.au/help/selling/getting-paid/registering-seller?id=4792&srsltid=AfmBOopqSBL0bVd...