Mostly a summary of the above replies... I can't deny that fear strikes through me when I contemplate such things...
This seems good to me:
1: Get the medical, without this you cannot go any further. I took any prior fears to a local doctor and got checked out for less cash. I've now booked the C1 medical at Gatwick for the 12th July.
2: To minimise risks of doing anything rash, do some aptitude tests such as those done by Gapan and Cabair (partial sponsorships). EPST? These will help put your mind at rest.
3: During, preferably before this - get some flying experience ... even gliding experience can go a long way to getting a good foundation knowledge for less cash.
BTW: HSBC offer Professional Studies loans that do not require a guarantee - i.e. your house. But you're still stuck with repayments if you fail so make sure you have a back-up career path.
Hope this helps;
SS