Teach you a practical head massage: comb your hair with your fingers, comb your hair from the temple to the back of your head with your fingers, or massage at Fengchi point from the temple to the back of your head with your fingers, especially Fengchi point. This method can not only treat insomnia, but also treat sleepiness. You can try.
English grammar may be your weak link, so you can spend more time to make up for it, so that you can keep up with the teacher's ideas and naturally won't sleep. You can find an English training institution, such as Tongmei Global International Education.