It sounds like this comes down to an inexperienced stylist, from a very different generation, meaning well but missing the mark.
As someone who holds weight on their tum and has spent my whole life covering it up, I marvel at the younger generation who often seem happy to just let it all hang out.
The stylist probably had good intentions in terms of encouraging you to feel confident and not focus on things but she clearly didn't understand the current weight of your insecurities or how hard it would be for you to overlook things.
If you can return the pieces, do.
Then I think you need to speak to good friends and family and ask for help in ascertaining what your GOOD features are and focus on them.
You say you are smaller up top? Then A-line dresses would suit. Or dresses that are tighter up top then flow outwards.
If you want to experiment with different styles and shapes, go thrifting. Try new things at home and get a feel for what you like and what suits you. Return what you don't like and feel good about not overspending and giving back to charity.
There are LOTS of SM pages with stylists giving tips and tricks for different body shapes.
I know that voice in your head is heavy right now, and not helped by your DH being a dick, but you need to give yourself credit for booking the stylist in the first place and trying new things.
Did it work out 100% great? No, BUT you did it, you like one of the pieces and hopefully you learned something you can take forward.
The vipers are great at helping out with clothes and finding nice pieces.
I'm sure we can have you sorted for those upcoming events.x.