I think that your work is atttractive and well executed and made with love and I am sorry that your Dad spoke to you in such a disrespectful way. I was also saddened to read in your update that you had not wanted to speak your mind to him because your children were with you. It could have been a good thing for them to see you be assertive and not to let him put you down like that, (but I don't mean to criticise, it is surely very very hard to stand up to someone when they hurt you like that, especially a parent.)
I am not from the US so to be honest I don't "get" this whole patriotic thing. I honestly do not understand how anyone could reject your beautiful work on the basis that it was "not patriotic enough for him".
To me, patriotism has really nothing to do with any flag. If he wants to show everyone how much he loves his country, how about being the sort of person whom a foreigner might meet and think "if all Americans are like that man, it must be a fine country!"
Hope I have not offended anyone, but that is what I think.