oh dear! first of all, take a deep breath! i'm sorry you're feeling like this, and for saying "quit writing" it must be a constant feeling, i think, and it really sucks. my advice is that you should take a break, don't really worry about the fest right now. just press pause instead of pressing stop, you know? do something else that you enjoy like watching a tv show or a movie, trying a manual hobby like painting or smt, decompress and then look at writing thinking about your feelings about it. try journaling or writing a diary or just opening a google doc to write about your thoughts on writing and the feelings around it. it might seem not like a good idea, but it can help you understand what exactly is going on. like, if you're feeling like this because you're trying to be perfect, if this new wave of entitled online "readers" that think they know shit is affecting you, if there's something else, etc. maybe like this you can have a better view of what is bringing you down and then you can think about solutions or other routes that can help you feel better.
personally, when i feel like this, i also do not engage with my own things. i dont open wips, or check the posted things, or even look at my telegram channel with my open ideas. just dont go there at all until you feel less anxious about it and when you can somehow see what is bringing you down. if it's because external reasons (ppl talking shit online and etc) try to remember that you like writing and writing what you do and fuck these ppl (scream to the voice in your head that agrees with them), if its internal reasons (you're comparing yourself with someone else, you need it to be perfect, etc) take a deep breath and remember that your own style is what makes it beautiful even if you don't believe in it, no one puts the same seasoning twice in their food so there's no reason to write like someone else! and also scream to the voice in your head that says such things.
take it easy, but press the pause button instead of fully stop right now, ok? don't worry about the fest, it's ok to drop the prompt if you need, and can switch to the bingo that is tecnically low pressure, or you can even try again next round. focus on you right now, darling. i'm sending you a virtual hug, and i hope you feel better.

(and im sorry if theres something wrong here my brain stopped thinking in english midway x_x)