I'm all for the message of "get help if you need it," and it sounds like OP needs the help of a professional, so I upvoted your comment. But minimizing the triggering event is not helpful; the things you see as trivial or unimportant might be insurmountable or critical to someone else.
It's tough, it's like I feel attacked by the fact that I can't solve these in 5 minutes like the other folks I see on Linkedin.
Trust me - as someone who listens to coding candidates on occasion, the majority do not just come in and whip out answers in a couple minutes. Those people are rare. And we sometimes like the slower candidates better because we get to see how they think instead of seeing just a quick answer.
It sounds like you are tying up a lot of your self-worth in solving these problems "in 5 minutes", and there a few things to unpack. First off is that "5 minutes" is a drastic exaggeration, and even if it isn't, standard interviews length is either 45 minutes or an hour - you get the full time, to work through the problem. So don't sweat the timing.
Even if you can't solve the problem, no one but you sees your leetcode performance, so just because you feel like you're failing, that's a feeling which is all in your head and it's trying to trick you into giving up. Don't let it. No one is getting hired solely on the basis of their leetcode profile.
(If you've already shared your leetcode profile with all of your friends, and/or feel like having a strong leetcode profile is going to make you a more attractive interview candidate, then make a new username not related to anything else you do online using an anon mail service (eg mailinator.com). Then, if you still feel the need to show off your speed on your leetcode profile, copy and paste the working solution from that username into your 'official' leetcode account.)
Instead of trying to rush through and do 100 problems per day, sit with one problem, for a whole month. Use different algorithms, do different languages, go for runtime speed efficiency, go for memory size efficiency. Use leetcode as a tool to help you.
Another thing to understand is that a large component of interviews is simply luck. There are only so many permutations of sum/sort/median/topN/bottomN/count possible, so during a real interview, if you get a question that's similar to one you've solved before, then a solution comes naturally. What leetcode really is then, is a gameified playground to see a bunch of variations on a theme, in order to raise the chances you see a similar problem during an interview.
Echoing other commenters about the subject of mental health - find a therapist to talk through this and other things with. My life's been better for it, and it absolutely helped me to get my life in the shape it needed to be, in order to get a job at a FAANG company.
Honestly, I'd recommend avoiding LinkedIn. It's completely devoid of any personal aspect to the work people do -- it's all business-this, company-that. There's no such thing as a post that's not spun in some positive manner.
As others have mentioned, in short, it's idealized. Plus, the skills that other people have are not necessarily the same skills YOU need to succeed. That includes Leetcode problems. Which, by the way: if the company cares about that kind of thing at an interview, they probably have that same sort of mindset during the job. Not guaranteed, but keep that in mind.
I struggled with impostor syndrome for a good three or four years, despite objective successes in my programming "career" as a student. I think that finding your own value, and distinguishing that from the skills you need to succeed, AND convincing yourself that you can get those skills, is the golden ("growth") mindset.
For example: math. (undergrad CS: calc, etc.) I tell myself I'm not good at math, I struggle adding basic numbers. but I've either 4.0'd or got 90%+ on midterms or just _passed_ enough math classes that I know this isn't true. How? I realized that math is literally just practice. That's it. Work in = work out, and if you get stuck, it's about correcting false assumptions.
That particular realization allowed me to embrace the (honestly terrifying) interview process a bit easier. Leetcode isn't about "grr get this problem perfect otherwise you're trash". Leetcode is about "okay, look, we have 20 minutes to see how good of a programmer you are, here's an intentionally hard problem. how clever are you. how fast are you. and do you fit our mold". THATS IT.
So, what could you do?
First, mindset. I've been doing iOS programming for a good 4 years now, but allll that work makes me worse at Leetcode, because I over-optimize for cases that don't matter. Realizing this made me slightly better at Leetcode. Only slightly.
Remember, Leetcode is just tiny, intentionally hard problems. It doesn't represent your skill as a programmer, just your ability to express a small subset of programming skills. And honestly,getting those skills is hard. I don't have an answer for that. Maybe try to analyze each problem, figure out what it's trying to test you on, then learn that topic from scratch.
Sorry for the ramble lol, hope it was helpful
If you want a Wonderlic type normed test - get in touch.