You'll regret it both ways.
You'll always have regret regarding your decision, should i sell? what if i sell and the price pumps?, should i keep? what if i keep and price dumps?
One of the lessons i learnt from my 3 years experience of trading, if you see something and you believe in the elements that made you take the trade, stick by it.
You can apply risk management if you want, personally, i don't use risk management and it almost made me a fortune, but it also costed me a fortune.