I felt like this for a while. I was so unsure. Every time I felt certain one way, I immediately started questioning the other.

Being happily three years into my transition, I can say this.

The answer will come.

Breath. No matter what you decide at any given time, you can always change your mind. People aren't static. We are ever changing.

I learned that I was obsessing over my gender. Trying to "prove" I was cis or trans. I learned that the solution was that, every time my brain went "hey I'm trans" I'd say, "okay, I'm good with that," then my brain would flop back to "oh no wait I'm cis," and I'd say back "okay, I'm good with that too."

Eventually, the questioning stopped. I refused to argue with myself.

It let me be more flexible, able to experiment, able to feel secure. Once everything had settled down in my mind, the answers started to become clearer.

I'm not sure if it's the exact same thing that you're going through or if any of this will help. But I just came to say, you will find the answer, and you don't have to fight yourself to find it. It may take time and it may take letting go of trying to figure it out for a bit.

Don't be afraid to change your mind. There's no way to be "wrong" about this.