Late 2017 and early 2018 i was holding lots of coins and tokens from the ico's in that some i really trusted with solution and team (not only me most of crypto community trusted). Now this coins or token became nothing . But some projects i entered to sell for small margin profit these projects given profit . So holding token or coin for long term is meaningless.
The year you've mention are the times where cryptocurrencies are trending. Since the trend, there are people attempted to make a project with crypto as a means of trading, making most of the projects are not as good as before. I can tell that you are based on ICO review sites, which are some people who rate it have low standards and not doing the review well even those heavyweights on reviewing have no idea that the project is shit. The aftermath of the trend is that more and more projects emerged, and mostly became shitcoins. It is just a pure luck having a great profit on the crypto scene nowadays and after that trend. I feel sorry for your lost. I know that it is cliche that research is the most you need to do before investing in crypto but it is the truth and also invest on your own risk.