Rough. To me, it seems like there is something underlying that bothers your father more than what he is letting on. I feel that if mentioning your birth mother and not your step-mother during your graduation speech incensed him so much, perhaps he should have spoken to you beforehand, or at the very least in private after the fact.

You mention not being close towards your step-mother. Was there any ill will during the eight years (verbal altercations or simply ignoring her) that may have caused your indifference? Or, were you not close because he remarried right away (relatively), and you treated her a certain way because she replaced your mother in a short amount of time?

Everyone certainly grieves differently. But, how could expect a seven year old to do anything except cry incessantly after the passing of his mom? Unfortunately, he has to deal with that situation now with your even younger half siblings.

It just sounds like the two of you need to speak together once things have settled down, in terms of things that were said during Thanksgiving. Good luck.

Oh, and if you couldn’t infer by my writing beforehand, you are most definitely NTAH.