Not to worry though, for those of you having trouble seeing your NFT collection, you can use the new feature provided by DappRadar, which now allows users to connect their MetaMask wallet and view all of their holdings on the Ethereum blockchain.
It's important to remember that if you bought something on OpenSea or Rarible or even a domain on ENS, all this information lives on Ethereum itself and not on any of those marketplace websites. The most thorough way to view it is on Etherscan.io, but it's not very visually stimulating.
Always remember to watch out for phishing scams when accessing this kind of stuff.
Have a good one!