Welcome Florentine! I think it's good that you decided to post here! It's a very supportive place.
And oh, dear, you are definitely not alone! Many of us GPs here walk on eggshells, whether with our DDs, DSs, DILs or SILs. This is partly, I think, cuz young people these days are likely to push GPs away or cut them off entirely for "offenses" we older folk often thought were "normal" or just something we had to put up with. Sadly, as you may have seen, some of the GPs here have already become estranged from their AC (adult children), CIL (children-in-law) and GC.
Fortunately for me, I don't have it as bad as some. But there are days I really have to watch my words. Through trial and error and what I've gleaned here on the Web, I've learned to avoid giving unsolicited advice, especially criticism, and to only answer briefly and to the point, even when asked for advice. If it has to do with my GC's care, often I find it best just to suggest that they ask their pediatrician instead. So much has changed that even I think that some of my ideas are outdated (sigh).
But I don't know if any of those are your issues. Do you feel comfortable telling us what has made your GP journey seem so "treacherous?" I'll bet you'll find others here who are facing the same things.