To be fair I never do my best during interviews. I always walk out of the interview thinking "Why the hell did I say that and not this?" That's normal. And yeah it's competitive, but you already got through the first major hoop, which is securing an interview. Then you passed the tests, which is another hoop. Now you just have to wait. Before the job I'm at now, I applied to dozens and dozens of jobs directly related to my degree. Only four or five emailed me back saying no. I had two interviews, both went well, but like you said it was competitive. They hired someone with a degree and way more experience. Best we can do is continue forward.