What to do about "stuck" transactions? (Copied from reddit)

Hey. I recently made a bitcoin transaction for the first time in a while. The transaction fees have gone through the roof (!!) since the last time I used it, and I figured it would be no issue to use the default fee on my electrum wallet (104 sat/byte).

I now realize this was a big mistake. My transaction is stuck in mempool and I don't know what to do about it.

What should I do? How long do transactions stay in mempool before they are not considered "sent" anymore and I can spend the bitcoins in another transaction? Is there a way to retroactively attach a higher transaction fee to my transaction?

I'd really appreciate any help with this. Having your money stuck in digital limbo sucks.
Already answered here on Stackexchange

You can find some additional information in the article

PS. Right now stuck about 0.07 BTC thanks to blockchain.info fee calculator. Just waiting, I'm not in a rush