Why is it so hard to get a job? 😭

I’m 18 and I graduated high school in May 2018...I got a job in November 2018 but it was only seasonal so a month later, I was again unemployed. It’s now April and I still haven’t found a job. I have anxiety and I don’t like socializing with people I don’t know. So I still went out of my comfort zone and applied to certain places and even got an interview at one. But I haven’t gotten any emails or calls on ANY of them. I honestly feel like a failure because I can’t simply get a job, but there are some 16 year olds in school that can. What am I doing wrong? I know I have no experience but I can’t get experience if I can’t get hired anywhere!!! And my anxiety is keeping me from applying to any fast food restaurants because I know I won’t be able to handle it. Yes I need a job, and yes I want money. But I also don’t wanna ruin my mental health by being miserable every single day.