I don't think you're being unreasonable, as one of your later posts said that what you were after, rather than free SW or meds (and Orlistat only works if you have a high fat diet anyway, by making you essentially faecally incontinent...), was a sort of supervised session at the surgery.
I don't think that's precisely a drain on NHS resources, and would probably serve the whole population, not just those on free prescriptions, better. That said, you need to figure out why you're overweight - it's not just eat less, move more for everyone - and try to tackle that: so if you're hoovering up kids leftovers, rather than binning stuff, work on allowing yourself to throw away food etc or whatever.
My mum found the NHS download 12 week thingie really helpful (she's an ex WW person from my childhood) - but if you're an emotional eater, something like OA might be more appropriate.
You have my congratulations for losing ten pounds so far - and my commiserations for needing to lose more: I am fat as fuck myself, and despite what people say, it's just as hard to lose two pounds a week when you're fat as when you're slimmer.
HOWEVER - I guess it also depends what your op is for: if you're classed as obese, apparently they need to have two anaesthetists present, for example, which is an extra cost. But there is also a significantly increased risk from the anaesthetic to you - so it's weighing up the cost/benefit analysis not just about the finances for the NHS but also for your health. If it's something to do with your joints and/or lower limbs, it actually makes sense to get you to lose first, simply because you'll be also at a lower risk of DVT following surgery, and also because your recovery will be smoother, as you are carrying less bulk and putting less stress on your joints etc
Good Luck, anyway - and again, congratulations on shifting nearly a stone already!