Baby screams and cries in car..

Alright I NEED advice, BAD. My son screams in his car seat until his eyes are swollen and he’s hyperventilating. I always check his seat for anything uncomfortable and have him strapped in safely. He has a huge mirror and toys. It’s gut wrenching and has completely made me avoid car rides. It’s not a whiny cry either… it’s a high pitched scream like he’s in pain.. I run the AC and make sure he’s comfortable, I’ve played music, talked to him, but NOTHING I DO IS WORKING. Pleaseeeee help.