Hi Sizhou! This is absolutely normal for anyone learning a new language. The more you speak with someone, the better it will get. Reading and writing are easy as you get ample time. But listening and speaking can be a bit challenging as your brain has to respond quickly. But as you said you are good with understanding English videos, that's really awesome. You're already one step ahead. Now you just have to speak English daily and your brain will start collecting the words easily and you'll be fluent in English. Thanks!