If you reached subconscious fluency in 2015, then your stuttering is now about 8 years in remission. The thing about relapses is, that we stop believing in our feedforward system, when you actually already realized that you are a non-stutterer. This is my take on it so it makes sense to attempt to put complete faith in your feedforward system again (without needing meds or that safe environment) and not worry about stuttering at all because that is what will likely develop the stutter disorder towards the "advanced stuttering" phase in my opinion