If you sell it now, your loss will be permanent. There is a chance that ZEC might be of high value once it has an ecosystem similar to BTC. But to reach 1 BTC again... that will probably take a very long time. Years. And it's not certain that it will. The price went way over the top because there was basically no ZEC available... and there will be a lot more soon, so the price will go down short- and probably midterm.