Found one major literature review paper, how to differentiate now?

First off: Using review papers as a guide line for your review is perfectly normal. What you should consider is, that even if the review is comprehensive, since its release there has been new research and publications were released that you should address.

Personally I don't think there is anything wrong with using review papers for tracking down other papers, but the least you can do is to also cite the review paper and remark that the review has a good take on the topic.

If you have any additions or own takes on the reviewer's opinion: do that! Discuss why you added other papers to your literature that the author neglected, give a different order to the topics if you prefer it, etc. In a historical context it might be difficult to change many things, but you should try not to copy it too much. As long as you formulate own sentences, your're fine.

In addition to ian's excellent answer, I would say that you need to clearly understand the purpose of your own research topic and the purpose of your own literature review to support that topic. I don't know how original your master's thesis is supposed to be (that depends on your supervisor), but if your topic is original, then no matter how similar the review article that you found is to your topic, there must be some aspects of your topic that are different from what that review covers. You must develop a very clear understanding of what these differences are. Then, on one hand, you should still read and summarize the articles that overlap with the published review, and then on the other hand, you should explicitly highlight other articles that the published review did not cover that you need to cover.