OK, one other point of view. And I'm not sure if this is a dreadful thing to do but it worked for us!
My little girl C is a total spoon refuser, and at about 11 months was losing weight. She would get v cross in her highchair and was obviously hungry but couldn't bear to be constrained into her highchair, got bored, threw her food on the ground, didn't eat, got hungrier and crosser,etc,etc. So....I asked for advice on the baby led weaning website and started giving her snacks as she played. So, breakfast in the highchair but as soon as she got cross we would get down, then about an hour later we would all have a drink and a piece of toast or something in the playroom. Same after lunch. That way she could eat without stopping playing and as she got better at feeding herself (and she's always been pretty good) mealtimes got easier and we only have playroom snack if we fancy it!
I think maybe your little one doesn't realise eating solids will stop him being hungry perhaps? Could you try something like this but with things that are really easy and fun to eat - blueberries cut in half, tiny bits of cheese, baby flapjack, muffins? Then just let him get the hang of eating without it being a drama and a stress. Like you I was v worried about making mealtimes stressful but now they are lovely!
I know grazing on snacks all day is a bad habit, but we did it for about 3 weeks and everything got a lot better. If the weather was nice we had picnic lunches as well, and meals out in restaurants too. All more exciting than being at home and so much easier for C to stay in place long enough to eat a meal!!