I found this site while researching possible side effects of cordyceps. I started taking it to help relieve an autoimmune disease. I'd take it with my evening meal and at night, horrible nightmares would ensue. I'd wake up with my heart beating very hard and the feeling I was going to die!!! Eventually, I'd go back to sleep only to be assailed by another nightmare and the feeling of doom! These were unlike any nightmares I'd ever had!
The same thing happend the following day when, again, I took the recommended dose of cordyceps with my dinner, so I stopped.
Reading your post, it makes sense! If dopamine and noradrenaline are increased (my body is highly sensitive) then the symptoms I experienced make sense.
Thought I'd share in case it helps someone else, since most sites claim there are no side effects whatsoever.
As for Rhodiola, when I took it in the past I found it had a calming effect, but it was very subtle, perhaps this is because I do not have anxiety.