Happy Birthday aah! Special days are sometimes the hardest to get through for us codies, but maybe do something extra special for yourself today, or take the kids out for a birthday dinner, and just make the best of it.
You sound like you are at a good point of "acceptance" and I know that, for me, I needed to get there before I could let go of the need to rescue what was not mine to rescue, and begin a grieving process of sorts that led to the road of healing.
It doesn't matter what his parents think, we each deal with addiction of our loved ones differently, and it sounds like they have not reached the acceptance level yet.
Keeping you all in my prayers.
And, again, :day1