Everything you described is pretty in line with my experience and I consider myself a stutterer. My speech is affected by how I'm feeling, who I'm talking to, if I'm tired and so on. There's times that I do stutter and then there's times that I'm fluent. English is my only language, but when I speak in an accent or even at a different volume that my normal voice my stutter is gone. It really is a strange beast! Hope this helped a bit 🙏