What is the difference between Furchtbar and fürchterlich (+ Beispiele bitte) ?Feel free to just provide example sentences.

I'd say that those expressions are idioms as far as the meanig is concerned.

To me personally, "fürchterlich" sounds more subjective, while "furchtbar" sounds more objective. "fürchterlich" is frequently used as "terrible" when one wants to denote that they personally judge something, while "furchtbar" denotes that a lot of people would agree that something is "terrible".

Unsere Nachbarn sollen endlich diese fürchterliche Musik leiser machen.
In der Ukraine gab es in den 30er Jahren eine furchtbare Hungersnot.

On the other hand, I personally think that "furchtbar" is always an appropriate substitution for "fürchterlich", while the opposite is not necessarily true. If you use "furchtbar" instead of "fürchterlich" in personal statements (like the one with the music), it simply sounds stronger (or maybe a little more judgemental). The opposite is not necessarily true, although a lot of german natives might not feel that strongly about it:

Der Holocaust war ein furchtbares Verbrechen.
(Der Holocaust war ein fürchterliches Verbrechen)

I think that many Germans would use "schrecklich" as "terrible" nowaday, though. It's honestly not something you have to be overly conscious about in my opinion.