Thanks a lot! I appreciate your advice.
However, Newcastle is much cheaper so you'd be able to afford a generally better lifestyle that might make you feel more comfortable and happy. For example, a nicer apartment that you don't have to share, more cash to save for a rainy day, etc.
I'd second that: work in a large company or a startup (if that interests you) in London for a couple of years to learn the ropes and build your career.
Then the world (or the North East) is your oyster. Or course, it's always difficult to move once you've settled down, even in London.