Suggest Treatment For Whiplash Followed By Memory Loss

Hello, I was rear ended by a car while stopped at a light on Feb 26. The person who hit me was traveling about 10 miles per hour, slid under by bumper and hit my tow insert. Most of the force went into the tow bar instead of the bumper like it should have. I suffered from a violent headache that came on suddenly about 20 min after the accident. Also suffered from severe whiplash and right arm pain - I already had chronic pain issues there. The severe symptoms have receeded a great deal, and I did and continue to seek treatment from a doctors. Over the last 3 days I am noticing moderate short term memory loss and a kind of confusion like wandering thru a store I know well and not really knowing what I am doing. I have always had not just a good memory - but a great one. Any thoughts about if this is normal, how long this will last, thing I can do to try to fix it? It has been 12 days since the accident. Please offer any thoughts on this.....thank you in advance. You can just answer me here if possible, you don't need to email me. Please help...