Take it slow. Install a VM with Mint. Play around with it. Get familiar. Move your regular usage over to it gradually. Make the jump when you are ready. It's perfectly OK to have reservations about a big change like that. But you don't have to do it all in one go.
It's not using it that's the problem, I have Mint installed on my work PC and my laptop, and I like it. But for some reason installing it on my main PC, which I use pretty much every day, has me worried for reasons I don't get myself. It's like a soft phobia, an irrational fear.
It took me 3 years from when I first started dual booting to when I launched Windows for the last time.
Take your time, move as slowly as you want, and always leave a way back. Eventually you might notice that you're feeling more comfortable with Linux than Windows, and if you're lucky, you might not even notice when you've stopped using Windows.
It took me over a year too. I was using a mini PC with Mint but still kept my old Windows PC under my desk. When I built a new PC, it never got defiled, though.
Dual boot? Keep like 200GB for windows, and the rest mint. If you need windows for something, boot over. But otherwise, I legit feel more worried when windows has access to my data.
Honestly this is the best suggestion especially if you can mount your windows partition read only. You get the benefits of Linux while still having access to your files.
For most folks, the biggest hurdle is getting compatible apps. Once you find the apps you need, moving over is just a backup and restore away.
I'm currently using Win10 IOT LTSC on my main gaming rig, and Mint on my laptop to get used to the environment (started 2 years ago). It's a great way to both get used to the new ecosystem, and have a fallback cushion if some software or scenario doesn't work properly.
Is it "change" itself that makes you uncomfortable or the fact that change means putting in effort in areas you've developed habits to minimize effort?