@Kirakux it's ok! Everyone has that! Even me..(lol I don't write haha) I can't even write a damn essay for my homework! I have ideas but it just dissapears when I start to write!
So don't worry about it! The ideas will come back! Meanwhile, you can try to read or daydream to get ideas!
I hope this helped!
Ps. I'm Keira2510 from deviant art