A basic is an introduction. A fundamental is a foundation. A fundamental is a premise, idea, or fact that an entire system arises from and is based on. A fundamental determines the shape of what arises from it, much as a foundation of a house dictates its layout. A basic is how you introduce people you are teaching to the system. It is a beginning concept, often simplified to assist learning. If a fundamental is the foundation, a basic is the front door to enter the system.
The difference between fear and panic is knowing what to do. If you have a reliable, effective solution then fear is an asset. You know what to do and fear just makes you do it faster. On the other hand, if you don't know what to do - or don't trust what you know - then you will freeze in terror, because you have no clear goal or way to get there. Fear helps, panic hinders. Fear is your savior, panic your nemesis.