As the one who got the BR cream trench ball rolling this season, I feel obligated to chime in! This looks fab to my eye, Sveta. I wonder if your worries about it looking too big could possibly be related to the light color? I'm thinking of Karie's recent post on the white shoes that looked too big. She worried that her feet looked "mutant" in them.
Do you think the cream color makes you feel "bigger" in some way? Could it be a matter of adjusting your eye? Maybe some other owners of cream coats could weigh in on this!
I suppose you could try a smaller size, as Angie and others have suggested. For comparison, my BR trench is a S and I'm a 4-6 in most brands.