It’s never going to happen is it

Hi all, severely depressed parent of a nonverbal 3.5 year old here. I’m losing all hope He will ever speak. He’s been in speech since he was 18months, and aba for the past 2 months. I just feel like things are just never going to improve. I get physically ill when I see parents of neurotypical kids, watching their interactions, hearing their conversations. I just am struggling. Just wanted to vent in a safe space.