I teared up reading your post and wish I could give you a big hug! You received wonderful advice from so many, so I will just reiterate that EVERYONE feels they are not good enough… everyone has these doubts. Some are just really good at concealing it. Do not be afraid of reaching out for help when you need it… ask questions, go to office hours. Don’t let your self doubt get in the way of your awesome potential and success. Best of luck to you!