is this a skin disease or somethng else

It's been over a year since this appeared on my legs, from just abovr the knee,down the front of my legs and on thetop of my feet.   The skin is developing darkened small lesions that are easily scratched off,escpeciallly when shaving.   they tend to bleed quite a bit.   My legs are terribly scarred from this.   The lesions don;t itch, they just look unslilghtly.   I have had biopsies that came back negative.   Now my doctor says it's stress.   I have been using a topical hydrocortisone treatment twice a day.      I recall that this problem started when I being to take over lawn care.   I used to wear shorts and the areas that are effected are the  areas where I would get covered with grass and dirt.
I live in florida, I can;t wear a bathing suit or shorts.                 Please help