I had hair similar to yours for probably the past 5 or so years. In fact, aside from hair, we seem to have overall similar styles. Anyway, I also am a big fan of 40s/50s style, particularly the hair. I finally got a cut about a month ago, similar to the first picture you posted. Mine has a little less length on top and I do sort of a side pomp. I felt really attached to my long hair for so long, but if I figured if I hated the short cut, I could always grow it back.
I was also terrified of going to an actual barber,but once I finally went, it was awesome. In my area, there are quite a few "old school" barber shops that specialize in those sorts of cuts. It was such a nice change and really, it's amazing how much of a difference a hair cut can make in terms of confidence.
I think you could totally pull it off and I can tell you from experience that it is so nice to have shorter hair now that requires so much less effort. If/when you do end up cutting it, post a picture!