It's never too late for anything. And it doesn't really cost you anything(except time) to try. Therapy is usually covered by health insurance, if it's not in your case or can't find good therapist, there is book called [Self-Therapy for the stutterer](https://www.stutteringhelp.org/sites/default/files/Migrate/book0012_11th_ed.pdf) available online, so i guess you could try that.