[Ethereum] Transferring Ether out of paper wallet

I created a paper wallet for my Ether a few weeks back, and have (stupidly) lost the JSON file that was created during the creation of that wallet. At the time I did not think that I needed that particular file, as I thought that like Bitcoin, only the public and private keys were essential. I do have access to both my public and private keys for my Ether paper wallet, and I'm now attempting to transfer Ether from that wallet to an exchange (i.e. Coinbase).

I've been attempting to create a new keyfile by following the advice in this post, but have been unsuccessful (When I attempt to run the "geth account import "c:\filename.txt" the console returns: "failed to load the private key – unexpected EOF").

At this point, I'm either trying to transfer funds out of my Ether wallet using only my public and private keys –or– I'm attempting to create a new keyfile that will assist me in transferring said funds. It probably goes without saying that I'm pretty new to cryptocurrency, so advice given in layman would be greatly appreciated!