Smileless and others, thank you for your good wishes on DGD2. The birth was actually very traumatic and it is very fortunate that both she and DGD are alive and well. A Christmas miracle, in fact.
Yoga, thank you for replying to me. I know the song 'Grenade' very well, have listened to it a great deal and have even quoted it on here - 'I gave you all I had and you tossed it in the trash' - because that's how it feels, doesn't it?
Sometimes, I think that the more you give to someone, the more they expect, and the less respect they have for you. In the same way as when someone is ill or depressed or troubled, or simply having a bad day, they snap at and take it out on those closest to them - because they can and know that they will be forgiven. Basically, they take our love for granted and, even worse, can sometimes use it to exercise power over us and engage in emotional blackmail, just as they did when they were toddlers.
Yoga, I was very interested in your DS's realisation that his treatment of you stemmed from a lack of maturity. I do think that because our DC assume adult forms, sometimes we credit them with more maturity than they actually have. Maybe the thing to do is to stand back and detach, to treat them accordingly, to give firm but loving boundaries. Be there for them, keep the door open, but do not chase them - let them come to you, which I believe they will, in time, provided that the relationship was sound before the estrangement. To do otherwise is actually to diminish the relationship and ourselves, as we lose our own self confidence and self-respect. And I think that, at the heart of a lot of these very sad stories, the basic problem is one of respect. There may be an element of brainwashing, as Yoga rightly says, but I also could never have treated my parents as DD has treated me.
Thank you also hugs for your usual insight and perception. One of the most hurtful things DD said to me is that 'SIL (then boyfriend) is my family now', which cut very deeply. In other words, that you are now surplus to requirements. But turning this round and looking at it in a more positive way, perhaps we are surplus for a while, as they mature and grow. If we have done our job as parents well, they have the confidence to move away and find themselves. As you so rightly say, hugs, true family and friends are those who care enough about us to not just say what we want to hear, but to say what they really think - albeit in a gentle and tactful way - even if that challenges us. But, in the short term, our DC may prefer to surround themselves with people who simply agree with them and, therefore, seem to 'get' them.
Pantglas, I am so pleased that you are back, as you tell it how it really is, and that the road to reconciliation can be rocky, that the relationship may never be what it was, or what you would have liked it to be, but that it can be good enough.
Rhinestone, I think you are absolutely right to put yourself and your health first. That is what we should all strive to do, pining and despair takes up too much headspace and stress can have a terrible effect on the body. Look after yourself for you, and also for those others in your life, from whom you are not estranged, but who love you, and care for you, and need you.
Christmas, both the good bits and the bad bits (and even most happy families will have some bad bits!) is now largely over, and we will soon be welcoming a new year. I hope and pray and genuinely believe that we will be reading here of more reconciliations during 2020. 
Just hubby and me I'm afraid this evening. Just seen our eldest son off with two grandchildren. Really quiet now. So wish we had somewhere to go to tonight to celebrate! Enjoy your evening!!!
. Can hardly wait.
. This time next week we'll be on the plane and on our way.
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, but like you and your DH, we'd be happier without it.