Smart But Comfortable Work Clothes Now I'm Fat

[ChocolateBiscuitsandaCuppa]

Am starting a new job next week. Over the last 5 years I've put on over two stone, and none of my old work clothes fit me.
I've been getting away with it the last few years by changing into scrubs as soon as I get to work, but that won't work in the new place.
Any advice re: mid-range smart dresses and trousers/tops that are ideally natural/breatheable fabrics that I can move comfortably in please?
I used to wear smart, tailored shift dresses but not sure if they'd still work as my proportion have changed.
Am 5ft 4 and quite chesty, and as of the last few years, have a bit of a belly.

Something like this:

Arket dress? They have a few more that might work.

Could you give a more specific budget? (Mid-range might mean Uniqlo or Me & Em. 🤷‍♀️)

I like Yours clothing for this sort of thing.

That's lovely, thank you!
And you're right of course re: budget - ideally around the £65 - £85 mark, but happy to spend more for things I actually like (like the dress you linked) rather than stuff I'm buying just because I need some smart stuff for work.