My child is not growing 😭

I'm a FTM and I have a son who's a year old. At his 1 year wellness check he was 19 lbs 12oz 28" tall. At his 9 month wellness check he was 18lbs 8 oz 26" tall. So he didn't really grow any.

So the doctor wanted to draw blood just to make sure he was doing good. All the blood work came back fine. Nothing out of the ordinary. So she started him on pediasure(2 per day). By week 2 of doing this I started stressing really bad because he would NOT EAT! So I called the doctor's office to tell them my concerns. They had me start giving it to him right before bed only. But had me go get a weight check. He was 20lbs 4oz.

Skip forward to the 20th of this month and he had another weight check. 20lbs 4oz again😣! His doctor wanted to talk to a specialist about his case. They told us to start giving him a carnation breakfast essentials before breakfast and continue giving him pediasure at night before bed.

He has a weight and height check on Wednesday and then he sees his doctor again on the 24 of December. If he hasn't grown as much as they would like then they will talk with the specialist on what the next move should be.

He doctor says that he looks happy and healthy it's just he's not growing. They told me to try not to worry to much, but I am. Yesterday I started writing down everything he ate and drank.

Everytime he doesn't eat it makes me feel like I'm doing something wrong. I try giving him different foods and my husband and I will sit at the table for an hour trying to get him to eat before we cave and just give him something we know he'll eat. Like chicken nuggets, pizza, pigs in the blanket etc. Some days he likes something then the next time it's gross. For example this boy loved Mac and cheese a month ago last week he wouldn't even try it and cried for like 15 mins until I just caved and made him fish sticks.

I'm losing it and I need help. Any advice, recipes, etc I would greatly appreciate it.

P.S. Sorry I know it's a long post so thank you if you made it all the way through.