“Lack of understanding the material I’m learning”
“Lack of focus and concentration on everything”
“While I get what they’re saying, the next time I completely forget the material I learned from them.”
“when I start doing exams I keep seeing different questions for some reason.”
Is it possible that you have an undiagnosed learning disability?
I agree that a comprehensive evaluation (physical/cognitive/mental health) might provide some answers for why you feel the way that you do and how you perform in the classroom.
Finally, don’t be so quick to dismiss the idea of trade school. It may be that working with your hands to produce tangible, immediate results might be more satisfying to you than the more abstract, long-term structure of academic study. Tradesmen also can earn very good salaries.
Best of luck to you.