I'm an over thinker too and transition and gender were pretty much always on my mind, nonstop, and boy, did I ever go back and forth. I am, I ain't, I'm this, I'm that. This went on for a long time, over a yr at least.
So no, I don't think it's abnormal to question or doubt being trans. It is a pretty big thing you know, realizing that you are trans and all the time, money, consequences that can come from it (if decide to transition).. It's a life changer. And it's like, you wanna be absolutely sure cuz some things you can't undo once you do (ex, coming out, changes from hrt, surgeries). But if you haven't lived that way (as opp gender), and haven't gone thru transition, how do you know what it's really like, how do you know that that's what you want, what you'd like? How's it gonna turn out for me? And on and on and on..
I guess what worked for me was just taking things slow, baby steps, trial and error. I knew everything involved in transition from being here but I tried to just focus on a few things. In my case, I always hated facial hair, hated shaving, figured might as well start on that. If I flipped later, no biggie, wouldn't miss it. Already was trying grow hair longer so kept at it, letting it get longer slowly over time, slowly adding more time in between hair appointments. Already had done herbals for awhile to give me some curves (feminize self) so pursued hrt (which took forever to get!)(all pre any trans knowledge..ya, still doubted self...silly me). That's kinda as far as I'd let myself think. Figured I'd tackle the rest if/when they came up.
I guess my best piece of advice would be to just take things slow, listen to and trust yourself, and experiment. Don't worry about labels, don't worry about what people may think (cuz how can you possibly know in advance?), just do what you think will make you more comfortable, make you happy, cuz that's really all that matters.
