My story is a bit similar. I was 39 before I bought any woman's clothing for myself, other than pantyhose. I'd have a shopping list with me, so I would look like I was buying for my wife. Most of my early cross-dressing was just wearing her stuff.
I wanted some flats, but was nervous about trying them on at the shoe store. Then I just suddenly thought that what was the store staff going to do, kick me out? So, I sat down, tried some on, and bought the ones that fit.
I'm still not all that confident, but it's getting a bit easier.