Can coronavirus penetrate the blood/brain barrier and damage the autonomic parts of the brain such that you actually “forget to breathe?”

This is not an accurate description of the sequence of events but, in effect, the broad answer is yes, that the virus can get into the brain and can influence the brain indirectly through its indirect effects on body processes including the immune system. So it is able to cause problems within the central nervous system and produce symptoms like seizures in those reaching this state of involvement. Fortunately, this type of symptom is more typical of severe cases that have succumbed because the people are in a weakened state to begin with and having vulnerability due to age or other medical conditions, so those remain the high-risk groups in terms of having a worse outcome.