@DearestEarrings Hey buddy, I think we all can understand the impostor syndrome, we all go through it from time to time. What I will suggest is to take a break, even a day may do wonders. Do something that will take your mind off of everything, go travel, dance, paint, watch a movie/series, read, anything that will help you releive that stress. You can cry too if you are feeling like it, this will help your body to release the suppressed/unwanted emotions.
When your mind has calmed down, assess your skills, give yourself that pep talk that you are going to make it, and your current situation is not the end of your life. The world itself is in chaos right now, and you are not alone feeling this way. Things are only going to get better.
And once all this is done, choose what you want to focus on, make a game plan, it should include whether you want to upskill while taking a break from searching for a job, or just keep on your search, that's your call.
Also make a point to go out daily to a park/garden, being surrounded by nature helps with the anxiety and stress.
All the best!