I got it to work, I found some links online to delete the mempool.dat folder, and restart Bitcoin Core through command line with a flag after it, then I was able to cancel the transaction, restart normally, and resend it. Curiously, I got 2/3 of the BTC back right away, and it wasn't until the next morning and sending the first amount of BTC that the remaining amount of BTC showed up. But it is on its way now with a higher fee.
I'm sure you're all relieved to hear this.
I am relieved to hear that you were able to get a way out of the situation but my concern is how you were able to cancel a transaction that have been sent for days just because it has 0 confirmation. I want to ask if that is only possible because you are using bitcoin core or its applicable to every wallet provider because if that is possible, a lot of scams can be avoided if its yet to confirm.