You reminded me of my first job.
Freshly out of school, I landed on a job at Subway. This happened to be the only subway in town with a god forsaken drive through, and we had a $5 deal with for 3 subs of your choices, and a rancid pile of shit computer that only handled one sub at a time.
They expected me to be able to memorize every order that came in, refused to let me write anything down for "Sanitary reasons", expected me to handle the drive through, balance the front counter, maintain the inventory stock, sweep and clean the front, and keep everything 100% perfect.
After countless mistakes of never having a job before, inability to do what they want, or be this golden employee, they let me go over the phone.
It was so hard, I went home crying every night with how badly they ran me into the ground, making me believe I was going to fail in life pretty hard. (There were other medical issues going on with me at the time)
I'm now 31.
I've had many, many jobs (Well over 20 now), and I've failed many times, but I've never stopped trying. I really, really wanted to quit, but as I had no one else to relay on, and trying to live like a leech of my parents would end with me living on the streets for being worthless, I had no choice but to push on.
Life will keep being shitty to you. That's a matter of fact, but as long as you stand back up, and keep trying, you'll notice it gets a little less difficult, and that's how you know you're actually growing as a person. The world experience will harden your resolve, and allow you to see how it'll work, letting you get the edge in.
Keep looking, and you'll find a job that works.
But that's the start.
Get a job that works, get work experience, then while your working that job, find a better one. Employers will see that you want to be better, and it will help them decide that you will be a solid choice for their team.
Keep doing this. You'll make it in life and be okay.
But remember, you have to keep trying first.