any advice ?

My son is 7 years old he always used to be a bit scared of being hurt. I didn’t believed it was much of a deal we all are scared of something but in this past year it aggravated a lot. Crying and screaming even i’m trying to clean his ears, when he has a tiny bit of scratch. He yells and cry if i try to cut his nails. ( No he wasn’t beaten, nobody hurted him if you ask ) For the past 3 month he developed a melanoma ( not cancerous) but i’ve been to 2 hospitals so far and they couldn’t operate it because my boy won’t stay to get his blood tests done first and put so much force the nurses couldn’t keep him. Nothing worked so far, the hospital only can operate him if he stays so the nurses can get blood test and he won’t even stay on a chair when at hospital bc is afraid. I don’t know, what to do anymore. We have appointment for another hospital in another city next week, i’m afraid they won’t operate him either and the melanoma is growing. I’ve been mor a month with him at a psychologist and it didn’t work a bit, but got worse. Everyone said he is okay and healthy but i don’t understand why he is this scared.

This morning i tried to clean his ears and yelled that i’m gonna k’ll him,when i don’t ever put my hand on him. He is also scaring my daughter of 4 years bc he got his fear to her also . Did anyone of u got into some kind of this story with their child ?