NeuroTalk Support Groups - Concussion and head pressure

Hi, I'm new here and I have a question regarding a concussion. I recently sustained a concussion 4 days ago, it seems pretty mild. I was hit in the neck during a full contact kickboxing class (he missed my helmet). My head snapped back and I got a slight cervical sprain and "mild" concussion. I am very fit and very active. I am wondering if it is safe to do any kind of exercising with my concussion? My symptoms seem to come and go. I was feeling fine this afternoon and thought I could do a few pushups and sit-ups, after I did a few I felt alot of pressure in my head and my entire body started feeling heavy. I thought maybe my blood pressure was going up. Any idea what that is and if there is any kind of "safe" exercise? I am going CRAZY just sitting here.

Thanks