N2P,
This advert from ACS in Scotland might help you decide to go straight for airlines!
They estimate around £16k a year for an FI. You would be better off working in McDonalds or stacking shelves in Aldi.
https://afors.com/aircraftView/44191
My tuppence worth. Do your three 12 hour shifts a week as a nurse (in Scotland, anyway) and work as a part time FI (maybe microlights? You could be microlight FI(R) for about £6k) and enjoy flying and teaching. Maybe even just do two shifts a week as a nurse on the bank, and you have a good basic regular income to sort out the bills and then do some flying.
Or go straight to the airlines.