Headache, dizziness, nausea, sudden blood rush to head. History of concussion and dropping weight on head. Serious?

I suffered a concussion about 3 weeks ago, dropped 95 lb weight on my head. I have been to the ER and my primary care physician and I do have another appointment tomorrow to talk about the fact that I am still in a lot of pain (headaches), dizzy, and nauseous. The reason I am asking you right now is that today I started having horrible blood rush to the head when I stand up or move too quickly. I have been doing very little - mostly sitting/ laying to fully recover. It's so bad that I have to brace on something or I will fall over and my vision goes completely black with stars.... It was so bad this morning that I actually ended up vomiting. Is this part of the post concussion syndrome? Is this something i should look further into?