|>>|| No. 398353
>People go through their lives without self-awareness.
This point I would like to put back to you. No matter how easy it appears, it's rather difficult to adopt a convincing accent, especially permanently.
I don't know how thick your current accent is, but even as a native speaker you might not even realise how much your true accent is coming through, especially when distracted.
I'd recommend just speaking as you do, and if someone goes 'where are you from then?' say "burnley" or whatever, and when they laugh or seem surprised, just say "my parents were from holland" and that's that, you're a brit with a bit of a weird accent.