wrongful death suit

i live in connecticut and have a question,my son was killed in a car accident and the driver had insurance,i was told that if i took the drivers insurance then i couldn't file a wrongful death suit.the insurance moey is owed to my son's estate.what does one have to do with the other?i was told we would be settling with the driver if we did that.that does not sound fair to us.then we were told we have 2 years to file the suit,so what's to the insurance money,do we lose it by doing that?could use some answers please,it would help us very much,thank you.