Peace doesn't mean that you will not have problems. Peace means that your problems will not have you.
Seek God first and you will find your purpose in the process.
The bottom line is pray. If you're tired, sick, emotionally overwhelmed—pray. If you're on cloud nine and life seems perfect—pray. If you lack direction—pray. If you doubt that prayer makes any difference—pray. If the circumstances of your life are out of your control—pray. If the circumstances of your life seem well within you're your control—pray even harder. Whatever you do—pray.