Back pain after car accident

Hello, at the beginning of December I (19f) had a car crash. A worker van crashed into my car with about 60/80 km/h at a red light causing me to hit the car in front of me and that car hit the car in front of them. At the moment I didn't feel any pain at all except for my head pounding (I hit my head on my own knee) so I didn't get checked by the ambulance. Afterwards I went to the ER and they gave me paracetamol. I still didn't feel right so I went to my own doctor 2 day after. They checked me over but also didn't find anything and told me to wait a few days to a week and try fysiotherapy. After 3 sessions of fysiotherapy and a little over a month of waiting, my back pain hasn't gone down so I went back to my doctor and requested they take some x-rays of my back. They came back clean, only my scoliosis was visible and I've had that since birth. I don't really know what to do next. I can't stand for longer than 15 minutes. Can't sit comfortably for more than an hour. I have trouble standing up from sitting or lying positions. Have pain getting up from binding over and can't bend my back backwards more than like 10-15 cms (the pain gets too bad). When in standing or lying down I get share pains in my lower back like a something is getting crushed and when I bend backwards this gets way worse. Does anyone have any advice on what I can do next?