>I've tried speech therapy during primary school but that didn't really help long term, **it helped for a brief period** That's totally worth something. It means something helped. Note that stutter management is ongoing, and needs to be maintained. >I never achieved 100% fluidity That's not the goal of speech therapy. I mean, it's nice if it happens, but the main thing is to enable the client to better manage their stutter. >I asked a speech therapist if it would be a good idea for me to join and she said that it wouldn't be much use since I'm already 18 and **therapy only really helps for younger kids** That's not true. I don't know why a professional would say that. Speech therapy has the potential to help anyone (given the right circumstances). Give it another shot, if you can - preferably with someone else than the ones you've been using (therapy tends to vary with the setting, and maybe variation is what you need).