Thankfulness is a state of mind, not an accumulation of assets. Until we can truly thank God for what we have and be willing to accept that as God's provision for our lives, contentment never will be possible. Reject a fearful spirit. Obviously, God wants us to consider these things and even plan for them, within reason. But when fear dictates to the point that giving to God's work is hindered, foolish risks are assumed and worry becomes the norm rather than the exception.
Contentment is impossible.
A Christian must consciously reject this attitude of fear. It may be necessary to face the fear to claim God's victory. If the fear is a lack of surplus, it may be necessary to live without it in order to conquer it. Seek God's will for you. Stand up to the fear.