Not permanent. Best evidence of this is that your fluency like ebbs and flows. There are good moments and bad moments. Good days and bad days. You're not going to talk your way out of it though. Seek professional help. There are SLPs who specialize in stuttering. People can and do improve their fluency. I was a severe stutterer until my mid 20s. Went back to speech therapy at that time and my fluency went from never-a-fluent-sentence to people I talk to every day have no idea I am a stutterer.