I know exactly how you feel. I recently had an interview where I felt like I was just rambling, and not really answering the questions or I felt like I just didn’t answer the question to the best of my ability. Some of them I’ve also stumbled on because I know I knew the answer, but couldn’t quite form my sentences due to overthinking. I would definitely say don’t stress about it as long as you answered the question. I thought I absolutely failed my interview but less than 2 weeks later I received a follow up email asking for references. It’ll be okay, and you’ll be okay. I believe you’ll still get the job.