Suggest Remedy For Severe Pain While Passing Stool

Hi Doctor!
This is mehak,and i am 19 years old now. And my weight is 55kgs. Its been from the time when for the first time i got my periods. and its since then that i go through seviour pain in my back, abdomen, legs,,some time in addition with pain in other parts as wel. i know this i normal,,but i guess mine is something weird.. i cant stand the pain untill i take two injections.. in addition one and half year back i used to get periods trice in 2 months,,lasting for 7 days,,though this short time period is quite solved now.. also its been 7 to 8 months that only when i get periods,,i experience a very seviour and sharp pain when i try to pass stool,to an extent that i automatically scream.. many of my aunts and relatives have been advicing me to quit taking injections,as later i might face many problems when i get married,,but its worthless,, because i have visited more than 6 different gynaecologists,, and i see no results... i really need your help...?
Also just now i noticed some white puss on the private part. could you please answer me what is it along with my previous question..?
thank you..