80% of all QCs are Oxbridge graduates. The Bar is insanely elitist and it always will be, there are just too many people with a law degree. If you come out with anything below a 1:1 alone, it's incredibly difficult to get onto the bar even if you're at Oxbridge (Which equivalent being 2:1 ofc.)
However, if you put the effort into it and get as much work experience throughout the 3 years (not just in your 2nd and 3rd) and push yourself as hard as you possibly can, it won't be impossible. You'll have to have some good connections, a lot of work experience, mooting and all that jazz set up on your CV and applications, but it was never going to be an easy ride from the beginning.