I'm not tryin to be a dick dude... But Motivation is something that comes from WITHIN YOU.
If there is something out there you want bad enough, you will do anything to get it.
whether that be waking up early before school to do your morning cardio, skipping out on chilling w/ friends to hit the weights, prepping food for one day for a whole week in advance..
quitting drinking to achieve your goals, quitting drugs to get the edge in the gym. whatever it be- you know there is something holding you back.
if you want to get in shape badly enough, you will do what it takes to get there brother.
the key is consistency. you're not gonna by zyzz after a month of training, hell, maybe not even after a year. quality muscle mass takes YEARS to build. day in and day out hitting the weights, day in and day out hitting your meals. Make it count brother, you can do it.