If you are carrying too much weight on your hands you will need to raise your bars or possibly change your saddle position. Is your saddle comfortable or do you fell like you're sliding forward? If it is tilted noticeably downward at the nose that could be a problem. A near level saddle is best. A short stem will usually manifest itself in cramped up shoulders and neck, as was the case with me. I went from a stock 100 mm to a 110 mm stem and it really eliminated those pains because I could stretch out a bit more. Much of this a subjective as I like to ride in the drops or hoods and my bar is 2 inches below my saddle. If your bar is level with the saddle as in your pic I'd say the problem is probably not the stem.