Hello!
Thank you for asking on HCM!
You prior pathological condition (with those very 
low BP values) seems to have been a very serious and dangerous situation for your life (regardless the primmary triggering factor).
It may have been associated with possible cerebral blood supply impairment, leading to irreversible cerebral tissue injuries.
So, there is a great probability, that your actual clinical signs (
stuttering) be a consequence of that dangerous health condition you have experienced the last June.
What I would recommend is: 
consult a neurologist for a comprehensive neurological status evaluation, coupled with a possible head 
CT scan or 
MRI (as is required), to identify possible cerebral damages, and institute an appropriate management strategy for your complains.
Hope to have been helpful for you!
Greetings! Dr. Iliri