I have been studying Korean for 4 years, but I find it difficult to make sentences. Can you give me some advice?

It's been 4 years since I started studying Korean, but I still find it difficult to naturally form sentences. I can understand everyday conversations to some extent, but I struggle to answer questions immediately and often end up responding in English. I am currently facing difficulties in constructing sentences in Korean. Listening is okay, but speaking is particularly challenging. I also experience similar issues when conversing with Koreans in areas like Gangnam or Hongdae. Do you have any tips or efficient practice methods to improve my Korean speaking skills? I especially need advice that would help me adapt in Korea as a foreigner. Thank you.