Seeking Advice For Interview

I am seeking advice or help from all of you. Currently I have 4+ years of IT experience. But the problem is that whenever I am giving any interview to switch, I am not able to answer any questions during the interview. But I know the answer to that question and after the interview is over I ask myself that I knew the answer but why couldn't I say it at that moment? As a result, the interviewers are getting angry and saying - you're wasting our time, if you don't know then why have you joined the interview etc etc.

So now I am afraid to give any interview, if the same incident happens then they will insult me again.

So I want to know from all of you what I should do in this situation? Because it has been 4 years and the current company is not increasing the salary, and there is no other way to increase salary except switch.