Commercial vehicle settlement advice

Hi everyone, so I just wanted to get some advice on if I’m valid or not and moving in the right direction. So about a month ago I was involved in a accident involving a commercial 18 wheeler that told without my car the 18 wheeler merged into my lane unaware of my presence clipping me to the front of his grill, dragging me down the highway when I’ve been spun off into the other side of the median I was transported to the emergency room on site where I underwent a CT scan and was evaluated and later discharged that night. The next day I woke up feeling extremely bad which resulted me and going to the emergency room again. This time more test were done. I received another CT scan. I received bloodwork urinary analysis and I was given three medications at the ER and prescribed for medications to pick up, I’ve been had to follow up with two more clinics where I received x-rays at both and prescribed physical therapy for three weeks which I’m currently doing and if my elbow does not get better, then I will have to get an MRI to see if any more damage was done. The only injuries that I really have is just my elbow. My lower back was hurting, but it has resolved itself. I had to miss a week of university during exam prep week and I have in severe anxiety while driving now to the point where it makes me nauseous . Of course I was low balled by the insurance company for a $20,000 settlement. I’m going to be asking for $200,000 as an anchor, but I know that $20,000 is not good at all. I’m going to be trying to negotiate by myself at first, but if they keep lowball me, I will get an attorney. What do you guys think?