@CrassJack why would you quit chess because of a single blunder? Well if you don't mind, in a game I actually blundered the entire game and felt pity for that, but didn't felt quitting chess at all. It is not because of a single blunder then you will need to quit chess. Blunders doesn't necessarily means that you have completely lost the game, blunder means that you will need to check your game, take you time, find what you did wrong and finally, improve yourself and make yourself new.
You aren't the only one that blunder something like this, I have also experienced it, in a game of the Sicilian I was playing as white and blundered the knight on d4 in move 4 or 5, I have found my mistake and I corrected myself for not playing that fast and keep blundering.
And please have this to keep in mind, every single chess game involves one player making a blunder, resulting the another player to win. So that tells you that every single game has a blunder, and it also tells you that you aren't the only one that makes a blunder, but everybody of us, every single one of us, including the chess grandmasters.
Chess isn't a game for perfection, chess is a game just for fun and allows you to gain knowledge, and chess isn't a game for you to quit that early. Keep studying with some help of teachers, opening books, tactic exercises, endgame tactics and/or anything that can help you to improve chess, as long as you don't quit chess.
@CrassJack again, you are not the only one, and you are not alone.
Come back tomorrow and make yourself new.