Humans are one of the most adaptable animals on earth. That means that we are never incapable of change. If you feel stuck in life, analyze yourself. Your eating habits, exercise, social life, etc. Write everything down, then decide what you are unhappy with. Then come up with healthy alternatives. Celebrate your early success (a day without a bad habit, then two, etc.). People are very receptive, they will see you are improving and will respect you. Start small, better than not starting at all.