I would also look up Dr Christopher Constantino. He is an adult who stutters, is a speech pathologist, and has his PHD in stuttering. One of the aims of his research is spontaneous speech and being (in general) more accepting of stuttering. There are methods to address stuttering, such as easy onsets and adjusting your rate of speech, but the likelihood of relapse is pretty high, because people eventually get tuckered out from the effort. His goal is toward being more accepting and reducing the anxiety and stigma associated with stuttering. As TheBrokenSlp said, the likelihood of this spontaneously recovering is more unlikely considering your age. Dr Constantino even has some YouTube videos you can watch where he interviews other adults who stutter who talk about what types of things helped them out in their own life. Stuttering doesn’t have to mean that you are a poor communicator; you still have interests of your own and things to say. This is easy for me to say as someone who does not stutter, but I am just hoping to encourage you to not change what you want to say and (to the best of your ability) be yourself. I’m sorry this is something that’s affecting you and wish you the best.