Instead of replying immediately when I get a text, I always wait a few minutes to give the impression I actually have a life and might be busy.
Why do you do that, don't you like the person texting you?
Yes, I like this one person and I don't want to give her the impression that I'm waiting for her text
If you like this person then you should be honest with her. Pretending you have a life is a waste of time. Why not actually do things in your life?
I don't want to treat her like she's number 1, she'll feel pressure.
If you like someone, you should be more straightforward. You are overthinking the texts, most people don't notice how quickly you respond. If you feel like you don't have a life, you should think about what you'd like to do to change that, too.