Last semester, I finished my practicum as a part of my college courses toward becoming a teacher. My experience wasn't great and really hurt my confidence about my ability to teach.
I enjoyed working with students one-on-one to help them with their work, and interacting with them in general, but instructing...
If you are going to teach in a government school do not worry about your performance. Government school teachers are not expected to do a good job.
If you like one-on-one work, I'd consider one of the therapies. There's an enormous variety of them.
This Wiki article gives you a list. It's important to note that the list includes quack treatments.
Lawrence Shatkin has excellent books on careers and college majors. US News and World Reports has an annual book on colleges.
There are many things you can do with an education degree other than direct classroom instruction.There are many companies the write curriculum and software for education, there are textbook manufacturers, there is tutoring, administration (principal, vice principal, various district office jobs - some may require additional experience, but could be long term career path) and many other opportunities. So before you go changing your major think of things you might want to do.
Sounds like you would make an excellent student counselor.
I'm no expert in the teaching field! I do a fair amount of speaking in public and presenting ideas though and if it's getting up in front of the class that gets you instantly confused and nervous and bothered.... seriously seek out "Toast Masters". I've seen it do WONDERS for people.
Only your college adviser can tell you what is needed for a switch in your major.
My niece started off as the reading teacher at her school. Helping those children who where behind. She meet wiht them in small groups.
You could qualify for school librarian.
Get further help from your professors. Seek help and do research on how you can do better in the classroom.
Re evaluate what you did in the classroom. What where your strengths and weaknesses.
This should show you, you have more work to do . Not to quit.