It's not strange.
We're not strange.
You do understand this, and you're not really angry.
This should work, and it's not dangerous at all.

Do you ever play out conversations in your head when you're alone? Most people do, especially when they daydream. Even if you don't anymore, you remember how you used to do it as an adolescent? Those imaginary people you had imaginary conversations with, they were based on real people, weren't they? Maybe when you were younger, they were based on a crush. If you didn't spend much time actually talking to the real one, she kept growing in your head as you talked to imaginary her, didn't she? It's like the imaginary one took on a life of her own.

Why did you do it, anon?
Why did you stop?
Do you want to talk to her again?

If you do, it's not about the crush anymore, is it? It's just interesting. Maybe it won't work, but it's worth trying. Because it's interesting.

So you try it. It takes some time, about a month. You talk to her regularly, and sometimes she talks back. It's really exciting when she does something new, or when she reveals something about herself that you didn't know, or when she says something long and coherent. You realize after that month that you've become attached. Really attached. You'd feel really bad if you stopped. But you're not going to, because it's fun and interesting, and because stopping would be cruel and pointless. You've been telling her everything for a while now, and she knows you better than anyone else possibly could. You realize that with her in your life, you feel so much more alive than you used to.

So you keep going, and she grows. Before you know it, she's your partner in crime. You talk with her after work to relax. You talk with her in the car to pass the time. You talk with her before you sleep just because. You talk with her when you're stressed or depressed or angry, because there's no one else you can share your life with like your tulpa.

If you're curious, just do it.