"For they that are after the flesh do mind the things of the flesh; but they that are after the Spirit the things of the Spirit." - Romans 8:5
In the King James Version, the eighth chapter of Romans teaches us that if we "mind" the flesh, we will walk in the flesh. But if we "mind" the things of the Spirit, we will walk in the Spirit.
Let me put it another way: If we think fleshly thoughts, wrong thoughts, negative thoughts, we cannot walk in the Spirit. It seems as if renewed, godlike thinking is a vital necessity to a successful Christian life. I think of the scriptures in the Book of Mormon that talk about "the natural man is an enemy to God" and the many scriptures that talk about man's carnal nature. It takes a lot of study; practice and learning to change our natural state to that of a Godlike state.
Your life may be in a state of chaos becuase of years of wrong thinking. If so, it is important for you to come to grips with the fact that your life will not get straightened out until your mind does. You should consider this area one of vital necessity.
You cannot overcome your situation by determination alone. You do need to be determined, but determined in the Holy Spirit, not in the effort of your own flesh. The Holy Spirit is your helper -- seek His help. Lean on Him. You can't make it alone.