Hello, I Am 19 Years Old And For About A

Hello, I am 19 years old and for about a year or two now I have been experiencing some discomfort in my abdominal area. On the left side of my body like around my waist area looks slightly swollen with a slight burning feeling and it feels as if it switch up sides. Like one minute I feel discomfort on my left side then it goes to my right side. But when I touch around that area, it does not hurt. The back of my left knee is swollen as well and both of my feet is slightly swollen. Now, I am starting to feel tightness in my throat like its making it a little difficult to breathe. I feel scared, please help me.