I used to just ramble about anything on mic xD or just games, you look really weird doing it alone but it's good practice to make good commentary.
Practice practice practice.
Try to imagine like your camera being like a best mate or something.
When I first started making videos I was really quite and nervous and it felt a little weird speaking to camera, but I got better at doing it over time. You will get use to talking to the camera eventually it just takes time.
Totally know what you mean. I don't record myself on camera for my videos, however I do record my voice which was extremely weird as I wasn't used to it. Weirdness, awkwardness, all of those good things may come at first but after a while of doing it you get much more used to it! it may never become as normal as not being on camera, but it will definitely get less weirder as you get used to it and do it more!