like you say - it is years of repressed grief coming out all at once.
i find it's better not to fight it. just let it out. like vomiting when you're sick - gotta purge the body of the toxins. it may get easier. for me - now i can cry without anyone knowing unless they actually look at my eyes and see the tears flowing - gently and effortlessly. heck - i started tearing up just reading your post!
you are BOTH that scared little kid AND the strong man - like BDD said - who is able to face and own the incredible burden that you BOTH have secretly carried all these years. by naming it, acknowledging it and pushing through the grieving process, you will gain a measure of freedom.
it ain't fun or pretty - but it's progress. go with it!
"That you are here - that life exists, and identity; that the powerful play goes on and you may contribute a verse. . . What will your verse be?" Robin Williams as John Keating in "Dead Poets Society"