@Guzzler - I'm sorry you're really struggling with this. I'm very slight, and am constantly managing my weight to keep it up, but I seem to have managed to to that now generally, although just the other day I decided to wear a pair of summer trousers I hadn't work since last year, and whilst my weight is relatively stable, my waist has obviously reduced.
In terms of meds,I attended a presentation a couple of months ago where an Endo stated that there are now over 400 potential combinations of med combinations for the treatment of T2. Of course, that's 400 combinations, not 400 different drugs, so there's a long way to go from Metformin alone.
Secondly, when you go for your HbA1c, would you consider having your thyroid checked? If your thyroid goes a bit dickie, you can lose weight without trying. Why npot ask if they'll do a good, wide bloods panel for you, just to ensure there's nothing that's influencing your weightloss.