Too much pain in periods. Soon for sure!

Hello Experts, Left side of belly I feel pain in periods too much I have too constipation problems, basically when I go for motion it's gives burn in my anal part Left side of belly just above panty line I feel something very hard stiffness, if I press it then it gives pain on other sides it's all normal It's from long time like approximately 1 year will complete to this.. because of this stiffness May b I might have lots of pain in periods too Now a days I am starting getting dark patches on my back side, also in underarms too Having lots of big big painful pimples on my face This all I observed and I thought to asked here to all experts Please guide me what to do, rather than consult to doctor which I will do soon for sure Thank you in advance