I don't know if I am cursed or something. If I sell a coin now from airdrop/bounty few days later that coins increases much that you will regret selling. If I hold a coin from airdrop/bounty again that coins price decreases much that you will regret not selling right away. I'm confused now whenever I sell the price increases and when I hold the price decreases. Am I cursed?

Nobody is cursed here, you are not just lucky enough to be on the right place at the right time. Suggest to hold all your tokens for a year then you can see the effect after that time because most probably coin's price will go up after some time.