For me there is a difference, particularly in the case of:I am thinking of examples in my head and yes that seems to be right.
E.g. I am scared of ghosts
I am scared by ghosts
They mean the same thing
I am scared of the thought of that
I am scared by the thought of that
Both mean the same thing
Thank you so much for the quick responses. Elwintee and envie de voyager expressed exactly what I felt.
Just to clarify, you can obviously say:
'I'm scared of telling her what really happened.'
but can you say
'I'm scared by telling her what really happened.' ? No. You can only be scared by a thing (that is to say, a noun).
It sounds somewhat strange to me, but I am not a native speaker.
Thank you very much for your replies!