I hate to sound pessimistic, but those GCSEs will be a struggle to get in. If you can manage 4A*s you are prob in the running, but without that it will be difficult. Unless you have other amazing things to your application, but even then it is difficult to compensate.
Things can get better in a year, so you may surprise yourself. If not, then there are loads and loads of other amazing unis other than Oxford. Best of luck with it all.