Taking short breaks when you can do breathing exercises, a short meditation practice or a 10 minutes yoga practice or something else that usually works for you or has worked in the past. Something else is grounding, you could do intellectual or physical grounding, for instance: walking very slowly and mindfully paying attention to your body's weight on each step; running cold or hot water on your hands or your face mindfully, drinking a cup of tea while paying attention to the temperature of the cup and how it feels,...
It might sound stupid or useless, but if you try some strategies (there are tons) it's likely you'll find something that works for you and really gets your mind off trauma. Once you feel better, then you can study. Grounding works best when it's done for a long time, 20-30 minutes maybe, but if the alternative is trying to study and not being able to focus for hours, then it's worth spending 30 minutes for self-care maybe? If that's not the case, then there are other self-care alternatives that can be really short (10 minutes).
Here are some things that work for me: playing some of the lumosity games (it's a website), 20 to 40 minutes yoga practices, 10 minutes guided meditation, self-monitoring feelings and thoughts (like in Harry Potter, the Pensieve - sometimes it works other times not at all), watching short, very funny videos, breathing exercises, imagining a safe place for at least 10 minutes, describing it in great detail with all the senses.
Good luck!