We use afraid + infinitive when we explain the fear itself: I am afraid to go out in the dark. He is afraid to travel by plane. They are afraid to cross the high bridge over the river. We use afraid of …ing when we see an unwelcome result of an action: I am afraid of falling. (= I am afraid because I might fall.) He is afraid of making a mistake. (= He is afraid because he may make a mistake.) They are afraid of getting lost in the forest. (= They are afraid because they may get lost.)

This is what a grammar book I use (Michael Swan. Practical English usage. Third edition) says at 299.13: To talk about fear of things that happen accidentally, we prefer afraid of + -ing. I don't like to drive fast because I'm afraid of crashing. Why are you so quiet? ~ I'm afraid of waking the children. In other cases we can use afraid of + -ing or afraid + infinitive with no difference of meaning. I'm not afraid of telling / to tell her the truth.

After " i am afraid to " there is a verb example I am afraid to die i am afraid to drive i am afraid to try it After " i am afraid of " there is a noun example i am afraid of death i am afraid of animals