Even though I am a straight white male, I will sometimes wear women's underwear.
Why do you wear women's underwear?
Because it feels better than men's underwear.
There's nothing wrong with wearing underwear made for women if that's what you like. You're allowed to wear whatever you want, because no one can tell you what to do with your own body.
I can't help but feel like I should be wearing them. I'm starting to feel more and more like I'm a girl.
Yeah, that's fine if that is how you feel. No one else is being hurt by these actions and so you're free to do it for however long you please.