well jenni, i am obviously in a minority, but i think you should follow your dream.
Just because others have tried it and it's not been for them, doesn't mean you will have the same experience.
I do understand when you say that this man is your true love. But if he is, why is he not supporting you?
If you are true soul mates, i believe you will end up together anyway as it would be unbearable apart.
Could you not have a small break? Say, 6 months where you try the london life and he can go to Spain. After all they are only 2 hours apart.
You only get one life for goodness sake! Your London dream is obviously a real desire and therefore, i think, yes, you would regret not trying it. You'll never ever be in this position again - 23 with the world at your feet. Don't spend your old age wondering what may have been.
We regret the things we didn't do, not the things we did.
Good luck x x