Here are some things I have learned about reducing pain and suffering, learned from Buddhist teachers, from friends, and from personal mindfulness practice.
Holding Pain in Your Hand
When I feel pain -- fear, shame, guilt, stress -- I used to feel it strongly in my chest. It can feel intense -- "knives in" -- as if my ribs are turning in to my heart.
A technique I've learned is to visualize this pain as something you can hold in your hand, like a rock. When you are suffering, you can look at the imagined rock in your hand, looking closely at it, and saying - "I see you, pain. I see you, suffering. I am holding you in my hand. You are not in my heart. You can not kill me. Some day soon, I am going to be strong enough to throw you away, but for now, I see you."
Removing the pain from your heart removes its power.
A common type of self-inflicted pain is anger we feel towards someone else. You can read more about it here. See also trust models, as both of these concepts deal with how you respond to injury from others.
"The past is history, the future is a mystery, and the present moment is a gift."
Suffering is caused by thinking about what has happened to you in the past, or what might happen to you in the future.
There is no psychological pain in the present moment.
Sometimes when you are feeling dark, you should give yourself a small gift (could be simple), force your face muscles to smile, and decide to put off worrying until tomorrow.