I am now waiting for a response on the forum of the exchange. Earlier, I had resynced the SPV file of the decentralized exchange to try re-sending (in vain). But now, the interface of the exchange still has that re-send transaction pending. I imagine I have to restore the backup folder of the decentralized exchange I made before resyncing the SPV file, but I am not sure.
I am thinking I want to clarify the exchange part before I return to Electrum to broadcast and CPFP the 'Local' transaction.
Okay, so it's from a DEX, not a centralized Exchange.
Then you still have control over the transaction, the problem is it depends on the Decentralized Exchange's features.
If there's an option to export the address' private key, you can import it to a new imported Electrum wallet in "
New->Import Bitcoin Address or Private keys"
and bump the transaction using full-rbf by following this:
http://bitcointalk.org/index.php?topic=5474986.msg63198878#msg63198878But I'm not familiar with most decentralized Exchange so I can't help you with that.