The best thing you need to do is stop and just wait for the coins you are holding to increase to an amount wherein you can pay your mortgage. At first it is not easy but it will be worth it once you see the profits. And since bitcoin is trying to recover from the dip, take some time off and just wait.
Patience is the only key in this case if this man want to revere the mortgage price he had put in some business. As you have said, the market is down now but this is no time to worry, bitcoins are recovering gradually and slowly as the price charts have started their uphill journey. Holders must keep patience with them and only this one trait will enable them to make huge money later.
Yeah, his case is critical already and there is nothing he can do now than to have some little bit of patience and then see how it all turns out. Unfortunately, he has already lost a lot of money into ponzi schemes and now he has made a good call buying some coins and holding for the long of it at least at this dip. He should be able to get the best from them in a short while once the market recovers, but that was a very huge risk to take. However, I wonder why he had to choose Cryptopia ?
Keep calm, you should go to work to earn more income, along with hold the BTC and Eth the most potential co.
Probably, the world will get him busy and he would not have to worry himself too much over a situation he has no control over. The first mistake was investing in ponzi, but then, if he can be patient enough, he made a good decision investing in the top 20 as long as he ended up buying them during panic. I am sure even by now he should have started seeing some little profit on some of them.