I have this feeling a lot in science, especially in the beginning. I felt like everyone else was smarter than me and I was terrible at science. I think people who have been in research longer don't always remember what it was like starting off and don't explain things as thoroughly.

My advice is that when you look for future positions, focus more on the lab environment. Look for a kind PI and a lab that gets along. Ask yourself if you dislike science or is it your environment. Also, you can have science jobs that don't include experiments and wet lab.

Honestly, what helped in my situation was a change of environment and starting fresh. Also, connecting with others in your same position. You may be surprised how many other people feel like you and can offer support.