job interview help

I am a recent grad and looking for jobs, but I am really bad at interviews. No matter how hard I prepare and think that I did well, I always get rejected after job interviews. I am naturally a really quiet and introverted person and anything that involves public speaking or talking to people that I am not familiar with makes me so nervous and anxious. But I have been practicing a lot and really trying to get over my fear, but now I am getting really frustrated and losing hope. I really need some tips on how to become a better interviewee.

I am sure the reason why I keep getting rejected is because of my interview skills, because I studied abroad at a pretty decent school with a good GPA, and my resume is pretty solid.

Are there any resources, like a career coach or courses, that help with the job interviewing process or just the job recruitment process in general?