I believe you should. If you stop, how will you earn from this opportunity? Yes there are failed ICO's and it's just inevitable. But that's the risk we need to face if we want to earn big in this venture. There is no perfect investment. It's just a matter of being able to manage those risks to our advantage.
Exactly, there is no such thing as sure thing in crypto. Projects rise and fall and you just need to follow the signs when to do certain things. ICOs are very risky, everyone knows that but they're good for making money. One successful ICO can cover for 10bad ones easily. Averaging is the thing with ICO investments. You just need to continue investing in ICOs you think are good and in time you'll develop a nose for it.