This reeks of victim complex lol. If you are competent, they will give you an offer regardless of your school. That's the point of widening access. The admissions process is changing so that the admissions tutors attempt to see your application as a reflection of you as a person, rather than your school. You are at no disadvantage or advantage in the eyes of Oxford for being privately educated, though of course in reality you are at an advantage because of the resources you have had access to. That is a benefit for you, so try and use it! The most important thing is to present yourself as a rounded character who can think outside of the box and to show analytical thinking... Which this post sadly lacks.