I came the other way about 10 years ago, but am looking to go back in the next year or two (with a fair bit more experience than I started with!)
Given you're a fresh ink-wet CPL your chances of landing a job are much much better in Australia (Northern WA/NT), especially at the moment.
The mob I work for has lost 7 guys in the past few months to bigger companies, and I know another few from some of the other local operators that have moved up too (onto Skippers/Q-link/Alliance/RFDS etc). Given in another few months we'll be into the 'Dry' season you're best bet would be to pack the car up and try a Northern adventure. Put in a few years of remote and then head back to the big smoke.
The UK just doesn't have the GA scene compared to Australia. It's either instructing or you're in an ATR/737/A320.
Since Brexit it became infinitely harder (the UK is now a standalone licence with no work rights to European jobs), and with COVID sending a few airlines to the wall unless you have a chunk of A320/737 experience there's not much going there for jobs at the moment.
It's not ideal with your girlfriend but flying-prospect wise that's a fair appraisal of your prospects! If your girlfriend is Irish (Southern) or is European your odds are slightly improved, but for a fresh CPL, Australia, especially at the moment is still your best bet.