It just takes time
I hurt for you RP. Our parents are of a different generation, and see things as black and white, very little shades of grey. As much as they love you, it is a blow to all they have been taught, and no matter how old you are they will think of this situation as something they have done wrong.
Having read many of your posts and threads, I know that these two men in your life, are your life. They are good for you, and you are good for them. You take strength from them and they take strength from you. Right now you need their strength, love and support.
Once your parents see with their own eyes that you are the same person you have always been, that your marriage hasn't changed, that your son is still healthy and happy, things could change. Give them time. The same time you have given those people in your life that didn't understand.
Yes it means more, hurts more because it's your parents.They are supposed to love and accept you no matter what your decisions.But they are still just human beings. With human emotions, thoughts and feelings.
They raised a wonderful,open daughter, and they will accept the wonderful, open, daughter they raised.
Stay strong and believe in who you are. I haven't met you, and yet believe in your strength and wisdom.