Just wait or create another transaction with higher fees and broadcast it.
I tried sending BTC, but it's been at 0/unconfirmed since 9AM. It's now 12PM. I included a tax fee of 0.00000591 BTC. Is this normal? Is there any way to speeding this up?
I'm using bitcoin core
0.00000591 BTC is a low priority fee, minimun to get high priority is 0.0001 btc, just wait, it will be confirmed sooner or later
/kb.