Over weight. And to reduce weight.

I'm seriously suffering with over weight. My age is 26,my height is 5.5, At 2015 my wwight was 58kg,2016 im at 77kg,I'm now at 84kg, , the same weight on my delivery day I.e on Feb 7th 2017. My diet is very little but still I'm putting on 2kg weight per week.I'm giving feeding to my baby.im also suffering with psoriasis for last 7years on scalp, piles,low BP,along with all this large belly and stretch marks after delivery.My family history has so many health problems, my father is suffering with glaucoma since 12years,sugar since 5years,piles & my mother was suffering with fibroid in uterus since 2years.m really afraid of this problems as this all heridietry.pls help me to over come all this problems and to reduce weight.