1 yr old refuses to eat anything

Few days backs we started BLW (it took me so long because i was not ready for a messy baby and messy room every few hours!) and 1 yr old DS responded well and started to eat a good variety with touching, throwing, eating a few pieces here and there. Now from last one week or so he has stopped eating completely. He plays with the food and throws it all over but not a single bit goes in his mouth. If it does get into his mouth, he gags, coughs and throws up. we have got him checked him for throat infection but nothing. And the paed said its ok for kids upto 3-4 yrs of age to be picky and fussy, do not bother. We went to this paed for the first time (neighborhood clinic) as we are still looking for a paed, everybody is in a hurry! i know we may be way too concerned sometimes, but he is our first child and with no family support its does get difficult. DS has good weight may be that's why paed wasn't too interested?? DS is 10.8 kgs and in last 5 months has gained 1.5 kgs only.

Earlier too he was not a great eater, he used to eat, say, 5-6 small bites of bread (hardly abt 1/4th of a medium sized whole grain bread) but he ate. Few bits of fuits, veggies, some food from our plate he ate. Now, nothing.
I wanted to wean him off breast and had completely stopped breastfeeding during the day and continued with morning feed, night feed and sometimes dream feed. Now he demands bf all the time and i think i do not have that much supply. I just started with pediasure and i give him 200 mils in a day (100 mls each, twice a day) and trying him to drink cow's milk, which sometimes he takes sometimes he doesn't, total intake around 200 mils only. He doesn't drink much water, hardly few mils. if we mix juice he usually gets cough.

He diesn't eat properly, because of that doesnt sleep properly, has started waking up in the night because of being hungry and sometimes 200 mils of milk! and then the day routine gets screwed! its a cycle and last 7-8 days have been bad.
i am not worried about his weight but nutrition. Sorry about such long and confusing post!