Yes, this is a very common problem, and I have faced it myself. For a long time I studied English, knew the grammar, understood movies, but as soon as I had to speak, I was stumped. Over time I realized that the main thing is practice and regular live communication.
Conversation clubs and online classes where you can practice in a safe environment helped me. A very cool option is
go for english. There you can practice with teachers who adjust to your level and help you overcome your fear of communication. What I especially like is the convenient format of the lessons, you can choose from individual lessons or group lessons where you practice speaking in real dialogues.
If you have a fear of communication, give this resource a try. The main thing is not to be afraid to make mistakes, because the more you speak, the more confident you become. I found it easier to formulate my thoughts after a few lessons, and after a couple of months I was able to speak English fluently!
