When my LO's ask for me to feed them, I've put the food on a fork and then hand them the fork, so it's not all me feeding them, and they get used to the idea of them feeding themselves (they don't usually need my help eating, but occasionally they need that extra attention/help). I also usually watch them eat (sitting with the LO's), so I'm with them and interacting, and do whatever I can to help them without actually feeding them (I cut the food as needed before I give it to them). DS1 did go through a stage where he didn't want to eat dinner, have you considered that he's possibly not too hungry at his meals and you may need to cut back snacks or wait longer after a snack until dinner?
I've also tried to arrange dinner when I'm not nursing, or try to at least have it all prepared and ready for them, and then when they're busy eating, to starting to nurse. I've learnt to do a lot while holding a baby in one hand.
Also, DS1 and DD used to just eat and eat and eat, but at a certain age (not exactly sure when), they really did slow down and eat less at a time. This could also be happening to your LO, and he doesn't want/need to eat as much now.