Answer: There is no need to feel the suffering of others, but the suffering of a group of people with identical opinions so that your shared pain and common desire to find a connection with the Creator will bring you to discovering Him between you.
There is nothing else. Either you want the Light or you will become ill from discovering darkness, one of the two. You call this by different names, suffering, pain, illness, and the like. A lack of Light is the origin of all suffering.
If you have a Kli, a desire that is ready to receive the Light, to absorb it into itself, to be filled with it, but you don’t make the effort to fill it, then that is felt as suffering.
From the Kabbalah Lesson in Russian 1/3/16