Most of us get over it early so don't panic. You can change your attitude towards stuttering. This will be difficult and could take time, years, perhaps. By all means try the techniques, I tried a few when I was your age but they didn't work, all the knowledge about stuttering didn't help one bit. I became withdrawn, introverted, bookish and spent too much time in my own head, not necessarily through choice. I've never met an extroverted stutterer. I, like many us, was self enforced into it. I'm in my 50s now and don't stutter, it went away over a couple of years in my 40s. Not too late to change and have a more 'communicating' life. There's no easy answers to why it went away.