Hi & Welcome
The pain you've described sounds like it's coming from your lung...There's many reasons people have pain in their, "right side", including intestinal trouble, appendix, kidney stone/infection, even muscle spasm, however when you have pain when taking a, "deep breath" , most of the time it's related to your lung, possibly pneumonia, or even a collasped lung. Please see your MD, ASAP, because if it's lung related, the quicker you get treated, the better.