Students are responsible for asking what they don't understand and the teacher is responsible for answering their questions. When students don't talk, the teacher doesn't know where to slow down. So, if it's not too late to save the course, ask her anything you don't understand, go back as far as you need to.
Of course, if she doesn't listen or if she doesn't respond to students' needs, that's something else, and you might have to talk to the one responsible for the courses.
Here, we can help you by answering the specific questions you have and explaining what you don't understand.
Good luck and ask, ask, ask!
