Another thought re cash - if you get a nationwide credit card, you don't pay commission on foreign purchases.
Either make a single cash withdrawal once a month from HSBC to minimise charges, and put suitable spending on the credit card. Then, make a single UK BACS payment from the HSBC account to your nationwide credit card via switch or whatever.
Obviously, you'd have to have discipline and budget carefully. And, I haven't read loan T&C's, so just thinking out loud here...