I am new to Bitcoin (using Bitcoin core client) and I ticked the check box that said something like "send with 0 fee when possible". My transaction has been stuck in the unconfirmed status for 7 days and I don't know how to recall it to set a transaction fee. I searched Google and everything but they were guides for other Bitcoin clients and I'm scared of messing up and losing my coins. Can someone give a clear step by step on how to recall and add a transaction fee?
This is my transaction https://blockchain.info/address/19JL8rn56ZWGgqHibB4U11xqvc9pqdrykb