I used the Bitcoin Core wallet. So if I wait long enough it will eventually get back into the wallet? If so, how long of wait (days, weeks, months)? I'm not in any kind of hurry. I was just worried that it might be lost forever.
No,
Bitcoin core will keep rebroadcasting your transaction... This way the nodes will not drop it from their mempool, so it will not return to your wallet without an intervention. (abantontransaction or zapwallettxes, to lazy to look up if the spelling of those comands is correct tough)
If you post the txid, i'll see if viabtc is an option for you.