If you know any people taking the class with you, maybe try studying with them or getting their notes. I’ve both studied with people who needed help and taken people’s notes when I needed help, and from both sides I know that it can sometimes be embarrassing to ask but that people are usually very willing to give.
I’m still in high school so luckily I don’t have 150-page quizzes (YET- there are some teachers I wouldn’t put it past), but I know that what can help is, as someone mentioned, highlighting key terms. When I do that I then make a list of these terms and make sure I know them cold. Then I read through everything again and I tend to understand things a lot better and make connections between ideas a lot more easily. If you’ve gotten your quizzes back, you may want to familiarize yourself with the content and format of the quizzes to make sure that the way you’re studying is effective and to figure out what type of knowledge is most often needed (I’ve found that by me, for multiple choice tests terms tend to be the parts most often tested, for example, which is helpful because you can then just get familiar with everything so that you can recognize it and not have to straightforwardly memorize detail, and that for fill-in quizzes the questions tend to focus on bigger topics, which means that I generally skim over the tiny details. Of course, this is not universally applicable- these are just examples of ways that knowing the format of quizzes can help you study effectively). Also, if this is such a standard class, there are probably sites like SparkNotes with good notes and explanations of ideas. The only time I’d say that SparkNotes is a bad idea is if you read it INSTEAD OF reading the book assigned in lit. In addition, okay, but you do miss out on details and the general learning experience if you only read the SparkNotes. In other classes, though, they can be very helpful- I’ve filled in gaps in my knowledge with their notes in math, poli sci, bio, psych, history, etc.
I hope I’m helping! Bear in mind that learning disabilities are not one of my nisyonos- my methods may not be suited to those who do have them. Perhaps a special education teacher or even just a web site or support group can suggest ways that people have used to study well and effectively.
Hatzlacha!