Good luck with the consult.
I never wear make-up and didn't do much primping pre-op. This was mostly because I spent my entire childhood/teenage years wearing uniforms for school, so high school was always bland khakis and a white polo (which, for the record, looks good on NO ONE). We had the option to wear skirts, but they looked really horrible on anyone who had hips so I never did.
But when it came to my hair and personal style, I tried to be outrageous. I wore a lot of jewelry, ear cuffs, and had different colored hair probably once every few months. Purple, red, even blue hair! Any way I could stand out that wasn't through the pretty clothes I didn't fit in and couldn't buy was what I tried. When I see pictures of myself from then, wearing ultra sparkly, gaudy Lane Bryant shirts I cringe.
Now I wear nice dresses almost everyday, even in the winter. Once I was an average size, I realized that I could pick and choose. What a concept! It was weird to have options. I still have funky style. I love retro cut dresses and I have eleven ear-piercings and three tattoos...but I don't feel like I'm trying too hard anymore and looking desperate. I just feel like me. And that's pretty cool.
I hope that no matter what happens on your weight loss journey that you always feel confident with your personal style. There's definitely pressure for overweight people to not look "sloppy," but dressing well will pay off for you. At a job interview looking professional is crucial, in school your professors will take you more seriously, and you will ultimately feel more comfortable with whatever the day throws at you. If an unexpected opportunity to go somewhere fun comes your way, you won't be the one worrying about getting home to change out of your sweats first.