Yup. During my time of self-discovery, I realized that I always had trouble speaking. My mother told me that I was extremely quiet, rarely expressive. I knew how to speak, I think, I just rarely did it, probably because I had no clue when, where, or how to express myself. When I "found my voice", or wanted to express myself more (around 4 or 5), I ended up stuttering so bad until the age of about 11, 12.
There are multiple reasons for being unaware of this for the past three decades. One is that no one knew what ASD was when I was a child (early to mid 80's), so it never occurred to anyone to see a neurodevelopment expert about it (and then of course gender plays into this as well). Another is that my ADHD made me unaware of my autistic traits. Another is masking.
I deftly avoided having to speak many, many times in the past when it involved expression of thoughts, ideas, emotions, any time that required a bit of extemporization.
I am OK with scripts. I am OK if I rehearse. I am OK if I type or write with a pen. But I'm not OK with verbalizing.
I have found that since my autistic traits have become so much more profound in the last few years, speaking has become difficult, unfortunately.
When I'm tired, yes. It takes a lot of effort.
If I'm experiencing sensory overload, again, it takes a lot of effort to speak.
Shutdown/meltdown mode, I become mute.