Using coke
well, that's your first problem, but even beyond that, it's a rather ludicrous idea for a diet plan.

Coke is FAR too expensive to be using it as part of a diet, let alone use it recreationally like so many of us.

Furthermore, even if you do lose weight, it won't be the right kind of weight, and you'll look like hell soon enough. You want to look healthy, and doing coke routinely for even 2 months will have you looking scrawny and thin. Don't get me wrong, you want to look thin, but not crack-head-checks-sucked-in-skeleton thin.

My two cents though, do what you want, but the cost alone would have me throwing this idea out long ago...