Tbh if you and your dad are on good terms then he should be able to tell you more about your area + monies than any of us, as it differs massively from area to area!
I can see no reason as to why you should not put your 7k aside, as your living costs - get your head down and study for the "Knowledge". Take a look at what your dad has achieved! unless he is a womaniser,gambler (not that there is much wrong with that

) then he should have done better than most of us who live in the provinces.
If I had my time all over again - it would be the London "Knowledge" for me - go in when you want - go home when you want - start and finish whatever time you wish - and still make a shed load - why have the stress of
other peoples time scales.
In Cardiff 5 years ago we would see 7/8 limos (people out on the razz)on a Friday night and sometimes more on a Saturday - these days a rarity of any numbers on a Friday and once in a blue moon on a Saturday - that tells you the state of the nations pocket, so why stress yourself out when the ideas that you have that generally turn out to be (with respects) nothing more than a pipe dream that many nurture coming into a trade that is going through a very bad time.
Having said that - if in your area (speak to dad) you see no sign of people cutting back - then go for it.