Here are my answers to your questions:
Question 1. within ourselves
Within ourselves here means that we may have fear inside us or some kind of fobia.
Question 2. cable = (in the past) a message sent by electric signal
Telex = a message sent by a telex machine (a machine that uses a telephone line to send message.
(Cambridge International Dictionary of English)
Question 3. He has promised to help me as far as he can.
This sentence means: He has promised to help me as far as he can (help me).