What Causes Severe Pain In The Right Breast?

Hi I'm a 20yr old female. For the past 2 weeks I've been having a pain in my right breast so I went to the hospital last week and they told me it could be a pulled muscle. They gave me naproxen which didn't work and now the pain is from my neck (right side) down to my lower right ribcage. And when I take a. Breath it hurts more. What should I do