Take a break. Sing some of your favorite English songs. Check out music videos here. Or try these bad lip readings 很爛的唇讀 below. I like Star Wars, so I think these are funny. If you can "sing" along to these videos, then you can read English very fluently.
After you have loosened up your mouth and lips with bad lip reading or your favorite songs, try to do the contest reading to these beats below. These beats will help you find the natural breaks in the long sentences.