Raising the cash is always a problem but there are ways. My brother is a little older but was in a similar predicament.
However, he managed to get a bank loan for to cover nearly all the training. He paid for his PPL himself and the bank has agreed to loan him the rest and don't require repayments until a year after the training is finished. Our parents had to act as guarantors meaning that if he fails to pay the loan off, they will have to - but at least they have equity in a house.
It might be worth doing the GAPAN aptitude tests and if they think you are good enough, that would be something to tell your bank manager. The test cost £150 and take a day. You get an assessment of your potential on the day.
Also if you got your class 1 medical (£400) beforehand that would show some committment to your bank manager as well as giving you some assurance that you are healthy enough to be a commercial pilot.
Hope this helps