Don't blame BJJ for your complete lack of discipline and will power. You got yourself obese. You have no one to blame but you. Now, I am being mean. I am a BJJ black belt. I am 54 years old, 5'9" and 165 lbs. I have done this for 24 years. You think you understand when you are clueless. BJJ is not an efficient way to lose weight. I look at our lineup and see it every time I go to class. Size is rewarded in BJJ. You can do BJJ and not lose a pound.
You need cardio, weights, and a strict diet so you can even get to the starting line. Walking to start, then bike or swimming. If you don't, you will die.
Not everyone gets to be an astronaut when they grow up. Especially people that have had no respect for their bodies. Man up and stop crying like a fat bitch. Your biggest enemy is Carl's Jr.