I'm new here, but I can let you know a little about how I sustained second impact injury. I received three concussions in close succession, but each were very hard hits that alone would have caused a concussion. In the beginning my symptoms were very pronounced, but improved over time. The neurologist I saw told me time was the best available healing method. Give it some time, and go from there. Try not to stress too much about it until your brain has had time to heal.