<human>: Can you summarize the given text in a few sentences?

im 19 years old, ~270 lbs, 5' 6", size 42 waist.

my doctor has recently noticed that my sugar is a tad over the norm and im not absorbing protein properly. they said there might be something wrong with my kidneys but i know its because im overweight. i've always been overweight since i was young. i went to weight loss camps, clinics, and other stuff when i was younger but i never really took it seriously. now im on the brink of diabetes and my self esteem is plummeting. 

i seriously think its time for a big change and i need a little help.

where do i ***really*** start? i dont want to browse magazines and hyped up fitness websites for crazy fad diets. i just want to know how to really start this process.
<bot>: im 19, 5' 6", and ~270lbs. my doctor basically said "change, or you're going get diabetes. where do i start?