Firstly, don’t worry, your Nano is safe.
The transaction is not going through because your wallet is out of sync. You will need to make sure your desktop node(on which your wallet works) is the latest version, upgrade if necessary and wait for the block count to catch up with the network. Make sure you have a stable Internet connection and your node is running from an SSD drive.
But if you wish to make a transaction immediately, it would be much faster to take your seed (which you should always have saved somewhere safe) and input it into another wallet app or service. For example, you can choose between https://nanowallet.io/, https://nanovault.io/ or https://vault.mynano.ninja/ for quick access to your account.