I have a MetaMask wallet and sent a bunch of transactions through with too low of gas. So they're stuck. They don't even show up as pending, they just are 'not found' on etherscan.
I've tried sending transactions through with very high gas price, but they don't go through either. From my reading (could be wrong) I need to resend the lower-nonce transactions with a higher gas to unstick them, and I can effectively cancel them by sending 0 ETH to myself.
However the only way I can find to do this is through myetherwallet.com and specifically by pasting the metamask private key into the website to sign the transaction (on https://www.myetherwallet.com/#offline-transaction)
Am I right about all this? Is there no secure way to send a transaction where you explicitly specify the nonce?