So, some bigger picture questions here.
Do you have a LinkedIn?
Do you love the company? Do you want to stay there? It sounds like you no longer love the role (due to its evolution).
If you're open to moving, check out LinkedIn and see what kinds of opportunities or recruiters might be sniffing in your area.
If you want to stay at the company, I'd honestly start by asking friends about open positions in their departments (if they like their jobs) or casually checking out the internal postings boards. I suspect it is harder to reverse engineer your evolved position than it would be to find a new position which could be a better fit for you. The other benefit of a new position is you change things up; just doing new and different things, breaking your regular work pattern/paradigm, usually forces people to become more engaged with what they're doing.
Have you read Dale Carnegie's How to Win Friends and Influence People? Don't scoff and call it manipulation; it's more like the dummy's guide for how to positively interact with people because most of us think we know all this shit and either forget or don't bother actually doing it. I've been rereading it myself to apply in work situations and sounds like it might help you with that personality gap you're feeling.
If you ended up where you are by going with the flow but you're happy with what you're doing, dismiss all hand-wringing that you didn't steer the ship. If you went with the flow and you're truly not happy - like really miserable, like "I don't want to go to work today" more mornings than not - then yeah, maybe try to steer your ship a little more.
I fell into a sub-banking industry by total accident straight out of college. After 7 years it turns out I'm pretty great at it and also love what I do...I didn't steer my ship here, I lucked into it on the current, but if I'm happy I'm happy. So - do you think you're really unhappy because you went with the flow, or do you just think a lot (I think a lot too) and worry that you should've taken more active individual ownership getting there because that's what other people and society seem to say you should've done?
Do you trust and like your manager, or have a mentor in your immediate department who you might be able to talk to about how your role has changed, and if that's typical/what might be a good way to change it back, or if this is just the career progression for your dept which you're on? Private, gently probing "just help me get an idea on how this works" sort of conversations with people you trust - don't go to your manager if he's going to start ringing alarm bells or interpret your feelings negatively on your year end review.
Them's my thots.
My life changes a lot. I usually move every year, plus all the other things. I tend to be more comfortable taking certain risks, like changing jobs or companies, not everyone might feel comfortable pursuing. As a whole, I would say - within reason, trusting your gut, take the risks of "big" change like different companies or even different industries when they come up - at first they're scary but you learn so much more on a macro perspective. (Ignore all of this if your job has great perks and benefits that are unlikely to be met elsewhere.)
Idk, maybe this was useful.