Here's a list of generic situations people get into, and ways to solve them.

"Girl X is losing interest in me, Help!"

let her lose interest in you. Don't be a controlling needy guy that does nothing but hound her.

"I think I fucked up, what to do?"

Fucked up how? If you disrespected her, apologize. If you're just afraid you lost her attention, don't do anything. Let her attention be lost.

"I got a response, what do I say?"

Say whatever you want. The fact that you think you have to say ANYTHING is showing you're being approval-seeking. Say whatever the fuck you want. And if you're too afraid to say something, say "I'm afraid of saying something." It's OK to be vulnerable.

"I tried all my magic tricks on her but she still isn't interested!"

Maybe she doesn't like you. Some girls won't, no matter what.