I don't know if its much help but my DS#1 was really slow to feed himslef. At the age of one he was put in a playpen with a chocolate cake and his Belly Buddy babies and just stood there while the other babies helped themself to the cake. He was ahppy to eat it if I fed him but refused to feed himself. He wouldn't even bit a sandwitch - we had to break bits off for him and pop it in his mouth like a baby bird.

Like your baby he has a sensitve gag reflex so I don't know if that is part of the issue, but he now happily feeds himself (he's now three). So you are not alone, at least, in having a child who won't feed themself