Maybe for some it is emotional. Others it may be physical. Many times for people there is a spiritual sickness that plagues all aspects of their life. It could be a combination of all areas. In your life every aspect: physical, emotional, mental, and spiritual are all connected.
Becoming healthier begins on the inside and works it's way out. You have to want to become healthier, really WANT it. Once you desire to be healthier, you can begin to look at small areas that need to be looked at and addressed right away.
Do not let guilt control your life. If you mess up one day that does not mean you have "blown" it. Get over that choice and move on and most importantly LEARN from it.