No one chooses to suffer (unless you are masochist), we only choose to allow ourselves to suffer.
Unless you initiate that suffering upon yourself, external forces are beyond your control, and your emotional or physical suffering are a natural response to that stimuli.
Suffering is simply a result of these external (environment, people, etc.) or internal (masochism) factors. In mental and emotional suffering, we do not have to allow certain things to hurt us.
Ofcourse, certain pains, like the Death of a Family Member or loved one, is too powerful for us to simply look past....that kind of suffering we need to endure in order to truly move on.....
Just remember....Suffering is not just a human thing. Animals suffer too, so suffering is a natural state of being. However, suffering heralds things, events, or places that we are not supposed to have, experience, or be in.
ex: If you set yourself on fire, you will burn and feel horrible pain for a few minutes....your skin is not meant to endure fire, because this will cause its destruction....your skin, by usage of nerves, will send signals to your brain in the form of intense pain, as a response to a harmful substance.
ex: As Human Beings we are social creatures.....social creatures need interaction, and need Love above all. Love (any kind of Love, parental, romantic, sexual, self love, etc.) is a necessary aspect of our lives. We NEED it to be mentally stable and develop.
If you lack love in your life, your mind will respond in the form of sadness, loneliness, or depression. You would not feel this kind of pain if you did not need the object of this pain.
Suffering is initially a result of not having a need and/or the result of being on the verge of mental/physical destruction.
Suffering then evolves to the form of a result of not having a want and/or the result of being on the verge of mental/physical boredom, when our needs are already met.