This is all psychological, and happens with everybody. I had lost 200 elo all in one session which made me unreasonably mald and continue to play more games, losing even more.
Always calm yourself down, take your time to process what's going on, both in and out of chess. Remember, do not play when you're tired or having a bad day. Cool off, and play from there.
why does it happen? it's every time. every single time. i had gained some 135 elo in a week, and nearly 300 in about 3 weeks. biggest loss streak i had was like 3 or 4. then suddenly, i started losing every game to basic stuff like backrank mates, hanging queens, hanging pieces, hanging everything, not seeing obvious traps, it's weird...
i fell down from 814 to 738 in a single day. not winning a single game. before i'd climb from 740 to 800 in a day too but. idk i just feel like i can't play the game anymore. this happens every time i've had a good streak and im so tired of never being able to just go upwards without just plummetting down