Feel like a failure /:

Hi everyone, I need some advice. I'm an early education major but I'm still taking my core classes. I'm taking 4 classes, as I usually do and I feel like I'm failing 2 of them. One of the hardest classes I'm taking is politics, I'm getting tutoring FROM THE PROFESSOR, and I'm still having trouble understanding. I have friends who are very smart who've taken the class and theve said it was the hardest class theve ever taken. I try to study and read but I feel like I'm just not grasping it. I take anything Civilizations class, and I failed 2 quizzes already.. It's weird cause the quizzes are easy but I think the teacher likes to make them tricky for some reason. His class is boring but it's all about reading ofcourse. I've just been feeling really down, and worthless..when I try to study I just think about how bad I'm doing and I can't concentrate anymore..I've struggled with a slight learning disability of reading comprehension since I was in 5th grade so I feel like it effects me a lot. Please someone give me advice