X-ray Shows Whiplash And Soft Tissue Damage After Car Accident. Have Nausea, Diarrhea, Back And Neck Pain, Dizziness. Will These Symptoms Go Away?

Hello, I was in a car accident on Saturday. We were in stop and go traffic and I was sitting in the back seat when a woman on a cell phone hit us going about 45 mph. I have pseudo tumor cerebri and had just recently gotten a concussion . After we were hit I spent the night in the hospital where they only did x rays of my neck and said I had whiplash and soft tissue damage. Three days later (today), I have REALLY bad nausea and diarrhea really bad which started the next day after the accident. With all the pain meds I should be constipated but unfortunately I can not stop running to the bathroom almost unable to hold it. I can barely eat, and although I ve been doing light movement, my neck and back hurt more and more each day but now my head is pounding my neck hurts and my arms and legs are hurting. I m EXTREMELY dizzy and almost lose my footing when I stand up and I feel like I literally lost my mind. I feel really stressed and can t remember anything. Should I go back to the ER or will all these symptoms just go away?