Alright. When you're writing a rap song, the key word is process. You don't want to pressure yourself that the minute that every word goes on a page you're writing, you know, a multi-platinum hit
The key is to first just get your thoughts out. One thing you can do is at the top of the page, just write the topic. "I don't love you anymore." So, from there, write out all the thoughts that come to mind that you want to say around that topic. The key is it doesn't even have to rhyme. You just want to get your thoughts out, and that could be your first piece of paper.
Then, you can start on another piece of paper, write the same topic at the beginning, and then take pieces of what you found on the first piece of paper and then begin to tell your story. Sometimes, you may reach a roadblock, where like, "God, I can't find a word that rhymes with such and such."
One cool thing that you could do is pick up the phone and call a friend, or have a partner who can help you, like, "Oh, I need a rhyme that rhymes with crazy," You know, and that person says, "lazy". Whatever occurs by having a partner there, it is helpful to have somebody to bounce off.
Another thing you can use is something called a rhyming dictionary, which you can find at any library or any bookstore. And inside of that book, when you have a roadblock, when you're trying to find words that rhyme, you can use that.
One thing to remember is you can start. You can write a rap song over a series of draft. So, you start one draft, and then create another draft, and then a third draft and just keep evolving it. But, a lot of people find it difficult to sit down and write a song in one shot.
It's okay to write through a process, by writing out your thoughts first, and evolving that to another page, and then evolving that to another page. And that's usually a process of writing a verse, a song or an album. You start off with your ideas, and then keep evolving your ideas until you have the final product. That's how you write a rap song.