I'm glad you now know better, Opt-In Replace-by-Fee is a good option if your money is stuck to push it forward. But reversing a Bitcoin transaction in your case after almost a decade is not feasible though I had read the suggestions of many people which might not work because of the number of years involved and they probably did not consider the wallet used for the transaction.
Next time, be sure of the payment, mempool and fees associated before pressing the Go button.
It has nothing to do with time... If you interprete the op's posts, it seems the transaction isn't confirmed. If the op makes sure it's never broadcasted again and he is able to spend the unspent output in a new transaction, his funds are safe and he doesn't have to "forget about the transaction". If the transaction ended up in a block 7 years ago, you would have been 100% correct since a confirmed transaction with more than a handfull of confirmations could be seen as irreversible (even a single confirmation makes it irreversible from a normal user's point of view, unless they're willing to spend a lot of money on a 51% attack or if they're extremely unlucky and the block including their transaction becomes stale whilst the block in the longest chain doesn't include their transaction)
Also, a transaction is wallet-agnostic, if you are able to access or export the private keys from the initial wallet, it doesn't matter if said wallet was created 7 years ago, you should be able to use the unspent output in a new transaction. Sure it's possible it'll require some extra steps, but if the value of the unspent output makes it worth your wile to take these steps, it shouldn't be impossible.