Cyberbullying laws require a school to be involved. So a slow clap for you for not knowing the most basic premise of the laws you think you’re going to “charge” him with breaking. Assuming that you know he’s the one posting this. Which you also can’t prove.
Defamation of character charges require the statements to be false and since there is plenty of proof, both hard and circumstantial, against you, and you have no valid defense (not to mention no money), good luck winning that.
Plus the fact that your crimes against him began in Washington state where they actually take rape charges seriously, before you moved to Texas, means that he can file against you under the Washington laws.
If I were you I’d just sit down and take it. If you don’t think any of what has been posted here or anywhere else is true then you don’t have anything to worry about. At least until you’re served with papers notifying you that you’ve been charged with the rape and abuse of an underage person.