Go back to work...and gain as much info as possible about their operation. Ignore the twats bullying you, I was always of the stance, " Lets finish this conversation in the car park, back of the store room etc".
Look for another job, but in the meantime, understand that you will be leaving very soon and enjoy winding the feckers up.
Look for ways of recording any illegal or immoral practices, with the view to reporting it to either the authorities or the press...everyone hates banks so the nastier the story the better.
Go back and enjoy yourself, try to **** the bank over as much as possible. When I left the mob I had a law degree and started working for a firm of solicitors...now they are a bunch of cnuts ! Very quickly I decided that it was a crap job, so spent 3 weeks having a great time trying to bring the firm to it's knees....eventually left on "Gardening Leave" after doing a Clarkson to one of the jumped up tossers..
Had a brilliant time doing this, so don't compromise your future by getting some quack to give you pills and a diagnosis that could **** the rest of your life up !!