After a few days of shell-shocked helplessness, I have decided this is not the end of the world. I did not feel overly confident in my skills anyway. This gives me a second chance, and the motivation to not just succeed, but do well.
If all goes well, I will graduate before June, and join the June/July intake of interns. If all goes extremely well, I'll end up at Liverpool Hospital (which I'm told is likely anyway), and I'll only have lost 6 months.
So, yeah. It sucks, but it's not the end of the world.