Weight issues? Unable to lose?

Since I was 13, I've always had issues. Before that, I was extremely skinny, literally like a twig. At 12-13, however, I ballooned... To a respectable 240 pounds. Since then, even though I am an active person, my weight drifts from 215-200. Regardless if I watch what I eat. I do not drink pop every day, mainly water, I have for years. Junk food is an uncommon occerance. I work at a golf course where I am constantly on my feet, raking, weed whacking, running when I can too and fro jobs. I eat 2-3 meals a day, toast or something quick in the morning (5:30 am) a larger meal of usually small chocolate for a quick boost of energy, maybe a burger or two, and iced tea (10am) and then a snack at 4am. I sleep at 7 pm. I am 5'11 1/2, I have been to my doctor plenty of times and he has no clue what is wrong with me. I get aches and pains too, and i can list medical problems if needed. I just want to be 170, like I should be.