I need help with my 4.5 year old’s whining

My 4.5 year old son whines and cries about everything. I am patient and I am calm for the first half of the day and by the end of the day I’m having to walk away from him to not tell him to shut up. It’s every little thing, he dropped his Poptart, his shoe is untied, his shirt got a drop of water on it, the dog licked his hand, he will whine and cry about it. And it’s impossible to talk to him about it. He just continues to cry. He won’t talk to me about his feelings or why he’s so upset. He also won’t hug me or let me console him. He goes to school and he also sees an OT for sensory issues. But I feel like this is beyond that and I don’t know how to get through to him. It’s so dramatic but I feel like I’m walking on eggshells around him so he doesn’t get triggered somehow and cry for the next half hour.