the amount of milk you pump is not an indicator of how much milk you have. The baby can get much more milk than the pump.
Can you take your baby in a dark quiet room to nurse?? that is what i did with my daughter. It seemed to help keep her focused on eating.. Sometimes I would have to lay her in her bed and let her get nice and drowsy and then pick her up and nurse her. I also went in her room in the morning and fed her before she was totally awake.
You could do the same thing at his daytime nap let him get sleepy in his bed then pick him up and feed him.
It gets very hard to nurse an older child. I dont know how some moms keep it going for 2 years.. My daughter was ready to be done at 9 months.. I kept her nursing till she was over 10 months. My son is 8 months.. He would prefer bottles. (he gets bottles one day a week from my sitter) He is probably about ready to quit nursing.. But I will keep him going a bit longr.