Anne, I don't know if this will work for you; perhaps not. But what has worked for me is to buy petite blazers and jackets. I usually size up in petite, but it fits better overall. I also have a slightly high waist and shortish arms—more reasons that P sizes in jackets, in particular, seem to work for me.
Interestingly, I find that I can successfully wear overcoats in regular sizes. I am not sure why that is.
Claire mentioned you should get a straight rather than a curvy cut. I don't find that is true for me; I like one with a bit of shaping. And it seems to work okay for me. I don't know if my proportions are the same as yours, however. My shoulders are about 98 cm and bust about 83.
So in many US sizes I will take a 4P in a jacket or a shirt, whereas in regular sizes (going by most size charts) I'd be a 0 or a 2. But the 4 P seems to work just fine, in fact better than fine for jackets and some shirts.