I don't know why my stuttering comes and goes in waves of being fluent from days, weeks to months.

I don't know why my stuttering comes and goes in waves of being fluent from days, weeks to months. Hey guys, I just found this sub because my stuttering has gotten to its worst since I was probably a teenager and I can't seem to get an idea as to why I am sometimes am very fluent for periods of times and then other times, I can barely put two words together. ​ For context, when growing up, I had a terrible stutter and could not hold a conversation with my parents, strangers or give presentations without wanting to beat myself over every word I stumbled on. However, since my teenager years, I started having this phases/long periods of time where I was just naturally more fluent, unconsciously. It felt as if my stutter was wearing away on its own. But time and time again, this period lasted only for a specific duration and returned, and so on. ​ These periods of fluidity in my speech sometimes lasted for days, weeks and months where I have/had the ability to say almost 70-80% of the words I want to communicate to really anyone with no conscious stutter holding me back. But when my stutter gets bad again, I find that my life goes back to shit and my mind runs 10000 miles per minute and analyzes everything during that moment. There is no doubt that in my adolescence, I have kept a heavy dependency on these grace periods of fluidity to get me through and now in my mid-twenties, I am realizing that my stutter can be and is as strong as ever. ​ However, I still want to know why/how I suddenly had these phases of almost complete fluidity/no stutter and if anyone has or goes through the same thing. ​ \*\*Note\*\*: I know a lot of people will attribute to less stress as a means to being more fluid, but I find this phenomenon is something bigger than that. It feels like almost a physiological change when I am more fluent -- such that my body is able to consciously draw more air and do so precisely when I want to speak and communicate. ​ Appreciate it.