I Have To 3 Concerns . I Have A Brown

I have to 3 concerns . I have a brown dirt spot in between my breast. I have tried exfoliating it for a couple months now but no change. 2. I also have a dark brown line on the back of my neck, last but not any less embarrassing I have a little hump in between my shoulders I need some advice what could it be ?should I go see a doctor about my concerns,? Is there something they can give me to take off the brown patches it's really embarrassing!! Help