To answer the op - you close your position - that is the market telling you that it is time to get out. There is no other answer for an investor or a trader.
You date shares, you don't marry them. Never fall in love with a stock.
Never, ever, ever let a gain turn into a loss.
Does anyone here rent a desk at in a trading shop in London?
Not interested in a desk at a shared office space sitting next to startup clowns - looking for somewhere surrounded by other active traders?
I'm over the sitting at home by yourself. Was fun for a while but you miss too much.