That is hard to overcome when you are shy. I am also shy and went on an exchange to Japan once. It is scary to try a new language but once you overcome the fear it is so fun! If you would like to practice English with me let me know. Good luck!

It is hard to be an exchange student. Say: Can I help you? Offer to help out like setting the table or sweeping the floor. Try to become part of the family. You may never have this chance again.

yu-u Your host family will be understanding. Even though you find it difficult try to seize the opportunity to improve your English skills. Perhaps talk to the most understanding woman in the household and explain that you are having trouble understanding. Perhaps show her your post on iTalki.

I totally agree with yu-u. The host family will understand your situation because you are not a native speaker of English. Think the other way round. If they have to talk in Japanese, they will have the same problem as yours. Therefore don't let yourself down. You are luckier than many other people since you have the chance to practise your English in an English environment. You know, the more you practise, the better English you can speak. "Open your heart" and tell them your feeling. You will have a memorable experience in your life. Good luck.