London and the "home counties" are probably the most expensive place to live on earth!
Over the years many nurses have relied on subsidies, and failed schemes like the Keyworker Housing Scheme, to help them afford a home, but the bottom line is that its almost impossible as an NHS nurse to afford to live in London unless you have a partner earning big bucks.
Many 'top up' their income with welfare, especially if they have kids. Like many of my coworkers, I used to live on a houseboat, as housing is just too darned expensive anywhere within a 40 miles radius of central London.
London property - Flats and houses for sale or to rent in London
If you want to stay in nursing, then I stand by my earlier suggestion of gaining RN experience first, then applying as a Community Nurse. once you are "in" you can apply to do the BSc as a Community Nurse Practitioner, and then will get you into Practice Nursing.
There is work in sales with the pharmaceutical industry, although not on such a big scale as in the US. Us Brits are not easily convinced of anything by sales talks and advertising, and so clinical choices and purchases are usually made after a search of clinical evidence instead. We would rather google something than listen to a sale pitch full of claims that can't be verified!
But there are certainly wound care product companies who have busy sales teams, meeting with teams of community nurses on a regular basis. That might be something to consider?
The nurses will tell it like it is, and be aware that many nurses are also prescribers, so listen to them!