Math doesn't make sense anymore

I am a freshman and I'm a math major. I am in calculus 1 and I don't understand what is being taught. At the start of the semester, I did. But as time went on it just got worse. It's really hard to pay attention to the lectures (because I can't keep up with the speed). and when I do, I would follow it until a certain point where it would suddenly stop making sense. I want to ask questions about what didn't make sense, but I know they are stupid questions. Like actual stupid questions or questions you wouldn't expect someone above 12 to ask. One day I just decided to ask at the end of class and the professor look at me like I asked him what 1+1 is. I think he looked at me differently after that, too. And the worst part is I have like millions of these questions. I try to watch YouTube videos, but they explain how to work out problems not the theory of the concept. I am very good at memorizations, so I've been okay on test. But I feel like I'm wasting my parents' money because I'm not learning anything. In high school I didn't care about learning and understanding because I thought I would do that in college. My plan was to transfer to a mechanical engineering major in my second year, but I'm realizing I'm not smart enough for that. My friends, whom I used to help with math, are in calculus 2. I don't know what to do. Any advice?

Author: No-Following-at-all