Don't.
First. You don't want to travel to London. Someone else wants you to travel to London and they hypnotized you to waste your time and money on something that is very unlikely to do you any real benefit. Realize that your desire is not yours and abandon it. Realize that ALL desire is not your and abandon all of them. Only rational intention is yours. Most likely, no ne ever taught you to be rational. I'm more confident of this if you attended school in the USA. So you don't have much of anything to go on. Study cognitive biases, logical fallacies, logic (including symbolic logic), software refactoring, and decision making. Read up on the concept of romanticizing and why we shouldn't do it. Realize thats what you were doing with the London thing. While doing this realize that some of what you read is absolutely wrong because the people who wrote it also did not have a very good education and were groping around in the dark. Lets thank them for that because with out them we would have a lot more groping to do in a much darker world.