Is true love real or is an illusion?

Is it possible for two people to be dedicated to each other and want to be with no one else?
I've lost all faith in the idea that true love exists. Marriage is a business, guys secretly want to sleep with women who aren't their wives, everyone is settling. At least, that's how I'm feeling lately most days. Anyone out there that can revive a cynic and give her hope?? I sure would appreciate it.