Feel your emotions without fear or labeling them. Mentally stop your worry habit, it's a habit you have trained yourself to do. Spiritually, read your bible everyday and actually believe and practice the spiritual self. Love yourself. Physically, go walk a little everyday until u can walk a half mile, then just go a little further every week. The endorphins released from your exercise will make u smile without having to make yourself smile. Of course the emotional, mental, spiritual and physical acts will all make u do that. And through self will and effort, this creates happiness.