What should a foreigner do when they find it difficult to understand Korean sentences in South Korea?

Question

I am currently living in Korea and continuing my Korean language studies. Recently, I memorized 2,000 words, and thanks to that, I can somewhat understand variety shows and webtoons. However, there are times when I know all the words but still can't grasp the meaning of a sentence. This often happens when I'm chatting with friends in cafes in Hongdae or Gangnam, or while shopping in Itaewon. It can be really frustrating.

In such cases, how can I better understand sentences? If anyone has had similar experiences, I would appreciate any advice on how you resolved this issue.