I'm hoping that, at some point in the future, my mental image will catch up with the reality of what's in the mirror. In the meantime, I have no idea what I look like.
For those of you who have made this transition, how did you navigate it? Did you bring a friend along every time you went shopping? Did you trust the scale, or measurements, or clothing sizes?
I know it's going to take time to get used to my new body, but are there things I can do to hurry up the process?
I didn't think this would mess with my head so much, but having always been overweight or obese, this is WEIRD. I went to Gap today to get a pair of jeans, and was embarrassed to ask the salesperson to help me reach a pair of size 6s. Surely she knew those would be WAY too small for me. They fit. Huh?

Not sizes, that's for sure. I have a size 4 J. Crew skirt that fits like a dream and an old (probably pre-vanity sizing) sized 10 Gap jeans that fit equally well. I wear small, medium and large sized tops.
I tend to wear larger sized dresses and smaller sized skirts.
I don't know that my mind every will catch up because I've been smaller than I am now and thought I was fat. Knowing helps though. I felt thin when I was definitely fat and I feel heavier now that I'm thin.

I sometimes struggle with this too and I've been maintaining for several years. In fact, I'm recovering from an injury right now and had a couple of months where my workouts consisted of just going up and down the stairs of my home. So I'm kind of in the same place as you right now. (except I'm constantly checking to see just how far down the fitness/hypertrophy continuum I may have fallen.