Sorry to hear but this is a fact. I have been a victim of this many times, But in forex trading. The point is to learn the lesson no matter how it is learned. The easiest way to avoid this kind of experience I think is if you exit a project and it gets pumped then at least avoid getting into it again or should wait for a long correction.
yes, and that experience seems to almost everyone who has been in the crypto world for a long time. the same thing happened to me too, it's just, the coins I hold, I never sell them, even when they hit high ATH. it made me regret when the price of the coin dumped so far. Even today, I still hold on to it. because from that experience, I always take the opportunity when I have made a profit, and avoid entering a project when the price is still very high, or still reaches its ATH.
So what is your point of buying and hodling if you won't sell them even at their ath? Don't tell me that you are just a coin collector? But I think it won't work on here since cryptos has a lot of supply and there are always people that are willing to sell their coins for some cold cash. What coins was that by the way? If that was btc, eth or other top crypto then the decision of hodling it until now can be fine but if not then you will have a slim chance for them to recover.
You only need a miracle and some whales may try to pump it up. The last thing that you said is correct however there are still people like the op who are tempted to ride a moving train. Some of them are already lucky to earn but they got greedy and expect for more so what they receive instead is a bad karma or a loss.