Cancelling/updating pending transaction - Coinbase

As you will probably be able to guess from this post I am a bit of a newbie to the scene.

I tried to make a transaction yesterday but set the gas price far too low, as a result the transaction has been sat in pending for nearly 24 hours and will likely never go through. The transaction was made using my Coinbase wallet and I can see there is no way to change the gas price or cancel the transaction.

I read a thread that mentioned trying to send a second transaction to myself with a higher gas price however that is also now stuck in pending.

I also read another thread that mentioned using a MetaMask wallet to send myself a transaction that should replace the transaction. When I go to do that I get an error message saying 'replacement transaction underprice' - does that mean this transaction needs to be more than my original?

Is there a way to replace, cancel or update the gas fees of my initial transaction?

Lesson learnto for the future, gas prices are very important!