hello..welcome to HCM iam dr N...... i understand your anxiety..pcod ,acanthosis nigricans are two conditions associated with obesity but not all obese people have these problems.. obesity can be due many reasons nutrional,heriditary,lifestyle,thyroid problems,harmonal etc i suggest you to see a dermatologist and rule out acanthosis and causative factors like diabetes,pcos,hypothyrodism,cushings etc even if it is acanthosis or pcod do not worry as they can treated and releived totally when the cause is treated see a dr and take other precautions like weight control.healthy low calorie diet,regular exercise,wt reduction on advice of the dr bye take care