Update: HE STOPPED CRYING!! First he stopped crying a few minutes after his parents dropped him off, then he started gabbing and smiling. Now he doesn't cry even while being dropped off. He still cries randomly for new reason, but I'm still learning his cues. I've also yet to hear him laugh, but he's smiling a lot and talking a lot. He's even getting excited! Today, his aunt picked him up from daycare and he didn't want to go! He cried for me when I handed him over! Made me feel SO amazing!
I'm still struggling with him crying when he wakes up with naps and that doesn't seem to be letting up, but we'll figure that out. I have hope! Yay!! Thanks everyone for your help!