M.M.
That's exactly what's happening. At 8mos, he doens't need to eat overnight. It's habit. He wakes up and you go in and nurse and cuddle him.
He needs to learn how to self soothe.
You'll need to do some sleep training - whatever method you choose. I'm a CIO proponent (close the door and don't go in until morning), but everyone is different. That is the fastest method to correct the behavior. Other methods will work, they'll just take longer, as long as your consistent.