Class, take out your notebooks and write it fifty times, until it sinks in: infatuation is not love, infatuation is not love, infatuation is n... fine, you get the principle.
You become infatuated with someone who triggers a very strong arousal in you.
You love someone who causes you to go through a very significant process with yourself.
Let's put it another way:
Infatuation is a state where someone gives you something you badly want right now.
Love is a state where someone apparently has the potential to give you something you will badly need in the future.