Hi Ellie
Sorry to say, my hubby was also told (by doctors) that prescribed paint-on treatment for fungal nail infections is pretty ineffective and oral meds aren't much better and can be unpleasant.
Apparently, under normal circumstances it takes a year (or more) for a large toenail to grow out from root to tip so that's probably why you've been quoted that length of time.
I hope you didn't contract the infection from the place you go to for your pedicures!
I'd like to be more encouraging, sorry. My big toenails are still manky over 4 years after the effects of chemo so I wear closed shoes most of the year and slap on varnish when they do see the light of day in the summer!
BTW, not sure how long the £20 dose of treatment lasts but that's actually very cheap compared to a lot of meds.