It is not easy to say do not give up while your capital or whole money is on a cryptocurrency that has been trending downwards for the past 10 months. Yet if the coin is solid and still hope the developers can fulfil their promise on the project then is worth waiting without given up.
You're not only doing panic sell but contribute for bitcoin to decrease the demand. Be a true bitcoin holder and do not give up. Ask for those people who did invest in December 2017 and they still hold their money.