Effie, I'm going out on a limb here. By wide, are you meaning you have some extra girth? A bit plump for your frame? And do you have a substantial bust? If any of that is the case you might be functionally narrow shouldered without really being narrow. And if you truly are narrow shouldered as well you might/probably need to start with a smaller pattern size and do both a full bust adjustment and what I call a full torso adjustment.
Do you select by your full bust measurement or upper bust? I've lost a lot of weight, almost 6 stone, after putting on over many years and sewing through most of it both up and back down. At my peak I became functionally both narrow shouldered and short waisted despite being 5' 8.5" with a 17.25" back waist and very broad shoulders. If I used full bust clothes were sloppy big in the neck and shoulders.
Using the upper bust measurement even now I'm 2 or 3 sizes smaller shoulder area than full bust measure puts me. I do fairly well doing a small dartless FBA, which is great for knits and adding on under the arm for my torso.
I can link you to dartless FBA info if you're unfamiliar.
BTW: when designer Diane Ericson was fitting one of her blouse patterns to me in class and said I needed to do a short waist adjustment I thought she was daft.
She was right, but I would have never thought of it. As the body changes we get to try all sorts of new things.....