You said you have short arms? Did they position your handlebars in relation to your saddle to accomodate them? Are you bending from the hips or from the waist? Are you curving your back to reach the handlebars? You should be in a neutral position and may require the handlebars be raised.
Are the handlebars short reach? Many WSD bikes include short reach handlebars. They bring the brifters closer to you and center you better over the bike.
Also, your saddle could be too high. Try lowering it slightly to see if that helps.
