My 21 month old refuses to eat anything

Hello everyone, I am new here. I have an incredibly picky eater. My son Danny was born early at 37 weeks (he was in the 3rd percentile, I was induced because he wasn’t growing). Ever since, we always had a hard time getting him to drink a bottle, and when the time came for food, it was even harder. He’s always had trouble with trying new foods. We first started with store bought food jars and eventually we switched to cooking everything for him. Needless to say, we continued blending everything for him and adding chunkier textures to his food as we went along. Lately, he’s been refusing everything and will only eat crackers with cream cheese and the occasional yogurt. Anything else we put in front of him, he refuses. He no longer wants to be spoon fed, and all the food we continued to blend for him, he refuses. He won’t even touch it. We give him enfamil 3 formula and keep it to a minimum of 4-5 bottles of 6 oz. I’ve tried offering him other food and it always ends in a temper tantrum. He’s had numerous ear infections and we’re currently in the process of possibly getting ear tubes for him (as per his doctor’s recommendation). He also doesn’t say a lot of words yet. Nighttime sleeps have always been random, sometimes waking up multiple times a night and other sleeping through. My question is, does anyone have a solution to his avoidance of food and how to get him to try new things? It’s become such a stressful stage in our lives and we are expecting again, and I’m just worried I will never be able to break this stage. Any advice is welcomed!