It's unfortunate your situation where you find it difficult to continue in the present job.
Your GM threats are illegal as he openly threaten you of a transfer to make your life difficult.
It is not clear from the query whàt is the exact matter which makes you humiliated.
Speak to a lawyer personally and seek a suggestion.
Quitting your job is not an answer ,when you are in adire need of it.
Sometimes fighting corruption while staying in an organisation is difficult for your survival .
The contract /the loan terms are crucial as you have taken it for the study purposes. Bank can take legal action against you and dad.so don't think about leaving , find a way out legally and if your suggestions in the bank against the wrong is not admitted ,ignore it ,you did your duty and now think about your job.
Even if there is a legal step you initiate ,the same will cost you and especially without job .
Before taking any step analise the situation and accomodate the best way.
Speak to any of the lawyers and discuss what is the exact facts .proceed only if there is a guaranteed solution.