Sensory issues in 22 month old

My son has sensory issues, possibly autism but they feel it is too early to give us a legitimate diagnosis. He is usually manageable. Some days are hard but the past week he has been so overwhelmed and has been screaming for hours each day. I do everything I can do, everything his therapists have suggested and nothing is calming him. I feel like I’m losing my marbles after days of not being able to calm my son. Do any mama with sensory children have any suggestions for what you do when you’re kids seem inconsolable?