hey man.. you and i are the same man, just age difference and a little bit of time between decisions...
I was 312+/- and about 36-38% bf two years ago next january... I am now at 220 and about 9%bf, maybe even a little less....
its about slow and consistant loss, not fits and starts, do not overtrain, do not eat less than a 25% deficit EVER....
i went through a couple of drastic diets before i figured out that its all about commitment, consistency and SATISFACTION: if you eat boring, you will cheat, guaranteed.
i can help, i have been EXACTLY where you are, just a lot older. I am 41 now. gotta sleep, but ask anything and althought i am no guru, i do a wee about how to help, and i have been there.
cheers until the morrow, mon. you can do anything. definitely.