My mistake seems to have been that by moving near my DIL, DS and GKs, I 'put all my eggs in the one basket' and by doing so I have often behaved like a 'bull in a china shop'. I underestimated my strength to put myself second and it wasn't clear in my mind that I was entering a space where a lot of things were done very differently to the way I do them. (Even though I had prior warning signs which I ignored!) I did this with the best intentions.
My advice to everybody who wants to go down this road:
THINK VERY CAREFULLY AND WEIGH UP THE PROs AND CONs AS MUCH AS IT IS POSSIBLE AND DON'T LET YOUR EMOTIONS GUIDE YOU ENTIRELY.
Here is what I did: I wanted to put the family first and myself second and offered help whenever needed. I've been with them for almost a year and still don't feel appreciated. For example when I do make a mistake by not telling them about a prior engagement, I'm blamed for 'letting them down'.This is how they feel and I must respect this, but in reality I'm at their beck and call for five days a week. Also my DS often tells me off for not doing things the way his wife wants me to. It is a really weird state of affairs and I had never experienced this is my life before (I'm 61 now and thought I'd seen it all!)
I have come to the conclusion that I have to go away and leave them to it for the time being and wait for things to settle.
I'm leaving with a heavy heart as I love the GC so much and I'm part of their lives now. I think under the circumstances it is better for all concerned to put myself out of the equation.
I wanted to share this with you in case you find yourself in a similar situation. Our family life to date was good