Hit by drunk driver with no insurance. now my insurance company is filing subrogation on me?

i was hit by am uninsured drunk driver and my insurance and the chp agreed it was his fault. my company payed my deductible and payed off my car. im filing an uninsured motorist claim against my insurance company for medical bills and lost wages. now i get a letter from my insurance company that they are subrogating me for money they payed out on the car. how can they do this?