ouch a sad story, buy 2 btc at 18k, now at 8.5k you've lose half of your total capital.
Hard decision is indeed between cutloss or remain patient waiting for the right moment to sell it. You only have one hope, which is to wait for the miracle of halving BTC next year, whether it will be the same as the expectation or far from the expectation. just hope it will be better.
If you invested during the market rally then that is the biggest mistake and if you see that the market goes down you have the option to sell off and wait for the market to be normal and then plan an entry strategy rather than holding everything, when you are investing the entry point in always crucial and many made a mistake when they started investing during the rally and majority are newbie investors who had no idea about the market.