I spotted the market was going down in advance, so i tried to sell my coins with a limit sell order - making a teeny tiny profit.. hopefully.
Instead I simply executed a market sell order, incurred taker fees and sold at a lower price than intended.
It does happen
You are not the first one man, and surely not the last one.
I once bought START instead of STRAT coin. START tuned out to be a long dead pump-and-dump project, so I lost some hundreds of $.
I left the day trading, too much stress for nothing, it was a life-lesson, tho.