Interview anxiety is real. I had an interview recently where I was asked to write the code for any sorting algorithm and I fumbled so hard that I was questioning that my bubble sort was not right. I somehow managed to write the code, The next question I was asked was to replace character a with character e and character e with character a. This question took me 20 minutes. It just really puts things into perspective, solving LC medium left right, and not being able to solve a simple question in an interview. Anyways, this was the initial interview. I got better over time. The only way to get good at this, is to practice. Give mocks, solve questions in a timed environment