Why has math become so hard for me?

I constantly try to think of the reasons why math has become so hard for me. Why do I get consistently low grades on math tests, or take home tests, or things that should be easy for me but aren't? I find it so frustrating and confusing that math is easy for me during class, and I understand it all because I am so focused, but when it comes to doing math work outside the class, or test time, I freeze and then don't do so well. Doing math work is one easy way to stress me out for the rest of the day, especially if I don't understand something. In middle school, or even elementary school, math was so much fun to me and I understood it, and we did group activities and worked with manipulatives. High school math was frightening and so difficult for me to do, I absolutely hated it. College math is totally a different story, and just like any college class, it's a routine; you go into class, sit at your desk, listen to the lecture and hear any feedback from the other students in your class, hand in the homework and then you're expected to spit it all back up on the day of the test. I think that a lot of students have trouble with math, and overall, I think the environment for learning math should be different than regular subjects and I'm sure many other students would agree with me. I feel like not just math, but many other college subjects are just taken so lightly because teachers expect you to just sit in their hour and 15 minute class and retain everything you've been listening to, but they don't realize that it doesn't just work that way. We are 19-21 years old and sitting in a classroom for that long listening to the same thing everyday gets boring and won't help us learn anything. But, I realize that math is so hard for me because of the way that it's taught. I realize that a lot of the material in class is very different when comparing it to a test or a quiz, and I will never understand why teachers do that and then get confused when we don't do well on their tests. If the material doesn't match the test or quiz, what is the point in teaching it that way? Fortunately, this class is a big difference than other college classes I have taken. Our teacher teaches us the material and then when it's time for the test or the quiz, I do feel prepared, but I still do get nervous. Generally, if the material that we learn in class doesn't match up with the questions on the test or the quiz, of course we're going to get it confused. I think teachers should teach exactly what will be on the test, just with different examples, and see how their students do compared to the tests they give where the material doesn't match up to the tests.