I am also a graduate and will be starting vet med at Glasgow this year. My fees are over £20 000 per year so I fully sympathise with your dilema. It is a rediculous amount of money over a short period of time and you will probably spend most of your working life paying it off but, if this career is the thing you have always wanted to do and will have a positive influence on your future happiness, then its something you can't really put a price on. If you can get a definite reason as to why you weren't given a place this year and find a way to improve on it before next year, then wait to reapply in Sep. But if you don't get an answer, I agree with others and say take the Bristol place. Fees will continue to rise year after year, the cost of living will go up and competition for available places is also going to rise. Ask the university about financial support (sometimes they don't mention all the burseries available to you), ask banks, family etc. It would be awful if you risked it all for nothing and when you were given a place, the fees were even higher when you had first been offered a place!
It won't be easy surviving at vet school while funding yourself and sacrifices will have to be made but don't let short term problems affect your long time happiness. If you want something that bad, you will find a way to achieve it.