Could Extreme Emotions And Mood Swings In A Child Be Due To Low TSH Levels?

I was told to consult with you. I have some concerns about my son who is 6. a brief description. He recently had blood tests done for his thryroid which came out with low TH levels. which could be some of the cause. things that have been going on... he goes from a normal playful happy 6 yr old.. to extremely hyper...extrememly emotional.. crying and sadness and goes into extreme tantrums that he says he cant control. he will cry and say I cant stop... he will calm and go back into just crying and tantrums.. and again say I cant stop. his moods change at the drop of a hat..just one extreme to another. school he is good..talks alot but nothing more then that so far. he doesnt eat alot..not much of an appetite. cant sit still ..gets distracted very easily. my son seems to worry about things he just shouldnt...adult things or things just out of the blue...what happens if someone dies or gets hurt...(no reasoning behind it though) he is very emotional about his dad not around... somethings may be part of it..some may be seperate.. I just want to help him.. try things to help him or get to the matter of what is going on. any help would be appreciated!