Hi Paulina,
Long story short, I 've known I was female since I was very young. I'm now 55 and still living as a male, though that is finally going to change.
I may or may not pass. I'll settle for being an ugly woman just to be myself. I worry about employment, especially at my age. I'm still trying to figure that part out. I managed this long. Could I go longer? I think I can. I also think that I can't die soon enough. It has been an existence at best. In my case, though, I have no doubt as to my gender.
If you have doubts, then let a therapist help you work through it so that you can determine who you are. Thinking you might be female is not the same as knowing, which I'm sure you're aware of. You still have time to find yourself. Good luck. Hugs.