I have a VP Shunt... Can i still be a Soldier?

I am a 21B, a Combat Engineer. I recently came home from my first tour in Iraq in Oct. 2010 with severe headaches that started half way through my tour. The army doc passed them off as migraines even though i had been through 4 IED's. Im 28 years old an have never had migraines before. One evening i passed out. My wife took me to the ER on post an they ran a CT scan an found out i had a brain tumor. It ended up being a Germinoma Brain Tumor. It was taken care of with radiation... thank the good lord. However now im stuck with a VP Shunt on the front right side of my head an the doctors are saying i cant wear a helmet. Well the Army i was raised in says no matter what your MOS your a Soldier first.... Well Soldier's have to were Helmets.... I just don't want to be chaptered out. I tryed to get some extra life insurance with USAA an they won't even look at me for 3 more years. Im perfectly healthy now but because of this preexisting condition im worried that i won't even be able to get health insurance in the civilian world. Is there any way i can stay in? Im breaking the news about not wearing a helmet to my chain of command tomorrow, im just worried about what they'll say.