What Causes Irregular Periods With Stomach Pain And Chills?

im a 22 yr old female. i have overian cyst with irregular periods with horrible joint pain in my knees( my knee pains started when i was 3 ive always had horrible cramps. my protien levels are low and my hormone levels are off balance. my period last month lasted 2 1/2 days which isnt normal there usually 5-7 days. i usually get it every other month. i get the cramps in my lower stomach about an inch under my belly button. the last 3-5 days ive been feeling extra cramped in my lower stomach which shoots down to my knees i get light headed when i stand i dont feel more tired its just hard to wake up. i cant eat like i use to food just doesnt even look good to me. i have to sit down after about 5 min of standing. i get the chills. my boobs got a little bigger and are very sore but arent changing in color i gained 2 pounds in the last month. when i stand to long i start to see black dots. when i first started my menstal cycle i would pass out. i first started when i was about 12 and havent passed out in over two years now.