From what I see, investing in ICO is like gambling but with lower risk but still more risky than trading altcoins. You can greatly reduce the risk by doing your research about the ICO you want to join, read the online review and talk with the team in the telegram. I think you should only invest in ICO that you have enough confidence and believe in the team. So, my answer is Yes, you should continue to invest in ICO.
Yes,you should and don't lose hope because theres still chance that you can get a big profit and patience to your self is needed to achieve it,so next time when you invest you must choose the best ico by researching the background of your chosen ico and you have to tickle carefully to avoid being lose again.