AFFLICT
Sufferers are afflicted with/by disease/troubles. It means to bring great harm or suffering to someone, including many invisible afflictions such as migraine headaches, grief, depression, insomnia, and painful memories. People are also afflicted with conditions such as arthritis, blindness, measles, and cancer.
Generally, we think of affliction as something that happens, rather than something that someone made happen. Generally.
INFLICT
Means to cause illness, punishment, etc. on living things or entities (group, area). Infliction can be major or minor. For example, a parent can inflict karate lessons on a child who prefers a more quiet exercise. Of course, it is probably a major issue to the child. Then think of the damage inflicted by Hurricane Katrina. And I know a woman who almost died: a bear inflicted horrific damage on her head/face/teeth … but she’s a “gutsy” gal.
Generally, we think of infliction as something deliberate. Generally.