Sorrow
Just as laughter is universal so is sorrow. Part of what makes sorrow so difficult is the loneliness we endure when are sad. Laughter is usually a shared experience but sorrow is found in isolation. Healing from trauma causes deep sorrow. This is not to say you should avoid it. The truth is sorrow is the underlying emotion behind any trauma. To heal is to grieve. Speaking from personal experience the hardest part grieving is giving yourself the permission to do so. There will be tears but they are necessary.