So you can't see the rest of your wallet. Have you downloaded the keystore? If you are only having a privatekey for your wallet and this is only related to the one address but if you have no seed and you will not able to open the rest of address that already contained in your seed.
You must know your seed to be able to open your wallet.
Based on the OP's statement that it doesn't store other than private keys, so I agree with the above opinion that there is no hope of returning all other wallets apart from the one that can be recovered from the private key that the OP has stored.