this week it happened with everyone whales were not trading actually in December giant investors don't trade much plus us economic news was coming that happened yesterday

$USUAL Guys, i got a question. Is it just my bad luck either that i have bad trading skills ( i really think its this issue but still, i want some advice from someone better than me in trading)
Every time i sell either buy it either pumps either dumps!
it happend with $XRP i sold to put in $UTK and when i entered UTK dumped and XRP next day goes from 2.3 to 2.7 and now with USUAL i enter at 1.23 and it dumps to 1.19. I really want to understand how to avoid this mistake in future. Any advice would help.