Nannakisses I said you were the third in the marriage, because, although you justify your actions by saying that you must always be there for your grandchildren, and in principle I agree, but at the same time there is providing a separate oversight and digging your self into the family to do what you call protecting, which is damaging to all.
Right at the start of your OP, you say of the planned weekend away Iv been asking her everyday for 2 weeks if she will please come Later you say When I do & have done EVERYTHING to help them all as a family & individually debts place to live big expensive presents & lots & lots of love, then I tried that I paid for a counsellor but they wouldn’t go sometime later I paid for a mediator which they came to we signed the agreements we had both agreed to. Then with weeks he went against what he had signed that he had agree
Quite simply, can you not see that all you say means that you are far too present in your daughter's marriage, and, as a result, they treat you like dirt - and you say that yourself.
Please, please distance yourself from your daughter and her husband. You can actually help your grand daughters much more by being less involved. As I said in a previous post. If you do, they will probably either shape up, which will be good for your grand daughters or collapse and separate, which will also probably be good for your granddaughter.
However the most important way you can look after them is being hyper vigilant about them seeing their maternal grandfather and not hesitating to contact social services or the NSPCC, if you think there is any chance of contact between them, whether their parents are present or not.
But do what others recommend, ring the Samaritans, A close friend has been a samaritan for over 40 years and I know their infinite capacity to provide both a listening ear and provide you contacts for support.