Thank you so much and sorry it took so long for a response.
I can't answer your questions about the nutropenia. However, I can relate an experience I had when my heart rate was as high as yours and I went for a echocardiogram (I also have a heart murmur from childhood and they wanted to just check it out). When I was laying on the table with my heart just beating away (from hyperthyroid/Graves), the technician asked me if I was exhausted from my heart beating so often? It never occurred to me before that, but I was exhaustd, just didn't know why. It probably didn't help that I wasn't sleeping very well - I could fall asleep at first, but couldn't fall back to sleep if I woke up for whatever reason. Beta Blockers (Toprol) eventually helped with the fast heartbeat until the anti-thyroid drugs kicked in and my levels came back to somewhat normal.
I was often confused during my very hyper stage - sometimes, I was a little afraid to drive, because it just didn't seem like my brain was communicating with the rest of my body. That is another scary feeling.
Hope you get an anser regarding your other diagnosis.