My brother with OCD is scared and homesick. How to help him?

Hi doctor,

My 19-year-old brother was suffering from OCD and it started kicking back in, for the past 20 days. He basically has a checking problem. He is currently a freshman at a University and was doing well for the first two months. Last month he went back home and was returning back to the University and that is when he started feeling homesick. During the journey, he felt for a moment that he going back to an unsafe place. This feeling was because of a crime movie that was shot in the city his university is in. That made him feel uncomfortable and at the same time the results of his mid term were told to him and he misinterpreted them and thought he scored less, but the real scores were very good and he did the best among his class. But he was affected by all these thoughts throughout the journey and right now he fights homesickness and is scared about the place he lives in and also checks continuously if he is able to understand what he is being taught in the class rather than listening to the class. I am scared for him and his future.