I'm in the process of going through something similar. I've have the D5100 for some years, with the 18-55mm kit lens, the 55-200mm zoom, and the 50mm f/1.8 G, with a Nissin i40 flash plus the wireless remote, a wired remote, and some filters. I just bought the Sony A6000 with the 16-50 kit lens and then the 55-210mm zoom, and I'm getting the 50mm f/1.8 next week; I just picked up a Sony fit Nissin i40 this afternoon and now just want to get some remotes and filters for the A6000 to complete that bundle. And, yes, it's all cost a lot of money.
The D5100 was getting a little too heavy to carry around so some time ago I got a Panasonic TZ70 as my carry-around (for the reach, not the image quality) and was having to compromise quite a bit with its plastic lens. And then I took the D5100 out again after a couple of years' break, got talking about things with another photographer, and fell in love with photography all over again. And looking around, the A6000 seemed like the absolute best choice for me. And one week of shooting with it confirmed that.
The A6000 is not only much easier to wield than the Nikon, it's a lot faster, finds focus quicker and doesn't hunt, has a top-of-its-class burst mode, is far better in low light, has a lot more features than the Nikon (many of which I'm tempted to use even though I kept the Nikon in A priority), and has me wanting to go out with it every day from now on. I shoot hand-held natural light street photos for the most part, but also like nature shots, architecture, and landscapes.
So, no, you're not crazy (IMO). And I don't see how you'll be missing anything, though I'm not familiar with the extra features of the 7100 over the 5100.
I might not be the best person to advise you, since I'm going through a bit of a photography rebirth, but if I were in your position, I'd just go for it.