First, congratulations on being accepted into the program! Second, I got dpdr last year and ended up taking a semester off to get over the worst of the dpdr. Now I'm back at school, in my fourth year of university, and it is definitely not easy. Sometimes I don't sleep enough and then feel like total crap while I'm in class and just can't pay attention. Other times I'm fine. It's also really difficult for me to study or work on assignments for long periods of time. My grades have dropped a bit. But I generally feel like the dpdr is less noticeable when I'm working on school. And it has been helpful to be back into a normal routine and living life.
Last year when I was feeling like how you described I realized that I personally would not be able to handle school while also dealing with high levels of anxiety and dpdr, so I took the semester off. I started taking an SSRI in August and it has helped me manage anxiety enough to go back to school.
Anyways, if you feel like you are able to go to school, do it! It might help you feel better if you are living life like you normally would, focusing on school instead of dpdr. And like the others said, just force the info in. It takes me longer to study and retain information (which is literally my entire schooling - biology is just memorization haha), but I get there eventually. And I take lots of breaks - I find I can only work for like 30 minutes straight, then I take a little five minute break. Otherwise I get really burnt out. Also I try to get a good sleep every night, exercise, and eat healthy.
I hope that was somewhat helpful. I wish you the best!