This is a very difficult situation and it must be very distressing.
I don't have an experience to share, but I have a couple of suggestions and hopefully one will help.
The first one is the seating. At 19 months , you can all sit at the table together so there is not the tension off him in a high chair and you in front of him, but just meal time and all the family members present in the house sit and eat .... the same thing.
This brings me to what he eats. I am French , DH is Italian and we have lived and raised children in different countries with sometimes very conflicting advice and menu, but here is what I love:
Start with lovely soup, which depending on how much water you put and how much you blend them can be very runny or dense. Soups are easy and tasty for the whole family. Carrot-pumpkin-onion soup, tomato soup (put 1 onion, 1 carrot, 1 celery stick, 4 ripe tomatoes cut into pieces , a bottle of passata, fill that bottle with water, a good quality stock cube and add it to the pot, cook for 45 min, last 5 minutes add fresh parsley, blend everything ) , then you can move to minestrone, with fresh veggies cut into the tiniest pieces you manage to chop,
You can also make a broth vegetables or meat broth, what in Italy is called brodo and is the based of weaning. in Italy. Once done you divided into portion. You can then cook soup pasta , starting from the tiniest like this one www.amazon.co.uk/s?ref=nb_sb_noss_1&i=grocery&k=puntine&tag=mumsnetforu03-21 Bring a portion of brood to boil in a tiny pot, when it is boiling, add the pasta and cook it for the amount of minutes on the packet. Once cooked, take a paddle of the brodo and pasta and pour it into a small bowl. Add freshly grated parmesan and a tiny piece of butter, mix well. Let it cool .
Then you can move to risottos. Boil 1 L of water and add stock in a container or use fresh broth if you have it. Chop half a onion and let it soften i a pan with extra virgin olive oil, add two handful of arborio rice, and mic it with onion for 1 minute, then add a ladle of broth and let the rice absorb it, then add another one, and keep adding liquid one by one until rice is cooked. In the last couple of minutes, add freshly grated parmesan and butter and a crack of pepper, and half a waffle of liquid, so the rice is still quite runny. Later one, it will be less soupy and more dry.
You can add, half a bottle of passata, instead of a paddle of broth, a hand full of pea, and even add some minced beef at the very beginning with the onion.
From there on, you move on to more varied food, adding fish and meat. You can boil some cod, and while it cooks, make a small sauce in a pan next to it, chop tomatoes, onions, fresh herbs, let them cook in a bit of oil, then add, a cup of water, and let the half of it evaporate. Then put a very tiny piece of fish in a spoon of the sauce and give it to him.
The French paediatrician told me once, never give your daughter something you wouldn't eat yourself, so always make something that is really lovely and hopefully it will be the pleasure he gets form the food that will help him overcome his fear and refusal.
Swiss paediatrician was strongly against pouches because eating in an all senses activity, and you don't see or smell the food. Most kids would totally refuse to eat the pouch if it was poured in a bowl because of the ugly colour and consistency it has, and because the pouch you suck and push the food against palate instead of chewing and swallowing. Let him be next to you while you prepare food, let the smell, noise of cutlery be part of eating and not just interruptions him from an activity to put in a chair with a plate in front of him.
Nice food is nice and can be shared by the whole family. In Italy, kids menu do not exist in restaurant unless it is a restaurant for tourists. Kids order half a portion. In Italy, kids from 1 year on, eat at the family table and share the family meal, their plate, will only be smaller, and whatever they have in the plate cut into small pieces or blended.
This is what I have taken from weaning my children and I hope at least one suggestion will help you. Ignore unhelpful friends.