I'm getting pitching/stabbing pains on my chest i have to breath slow bcus if i don't it will hurt more what could cause this pain please help it hurts ?

A number of causes:-: Left sided maybe heart related ; but at your age its not likely, other causes are a rib fracture (hx of an injury or severe bout of coughing), costochondritis (inflammation of cartilage part of the rib) {from a viral infection or an injury}, nerve lesion from a disc/ injury, lungs issues like pneumonia, pleurisy (inflammation of the lining around the lungs). See pcp if no relief with aleve/advil.