If my only goals in life were to earn a paycheck and watch sports then it would be hard not to give in to over eating, over drinking, and looking at porn. After all, if my goals were all self-centered then why shouldn't my actions be self-centered, too?
Alcohol and drug abuse, gluttony, slothfulness, and lust are all based in selfishness. They're all about making yourself feel better and disregarding others.
The best way to overcome these problems, and the depression that always accompanies them, is to start living for others. When we volunteer to help the hungry, the homeless, the orphaned, the widowed, and the sick we take the focus off of our problems. And when we're not focused on our own issues, then we won't be constantly trying to self-medicate them.
Be a big brother. Take a fatherless-kid fishing. Start an appreciation breakfast for your local police. Start a hiking group for veterans, or serve at a homeless shelter. Think beyond yourself, because a life lived in pursuit of personal pleasure is a life destined for misery and regret.
Don’t settle for just existing. Set noble goals, and live a life that will change someone else's.