Are all my symptoms related? Or is more than one thing happening to me?

[kkoper]

I'm a 19 year old woman, and recently I have been experiencing some very worrisome symptoms. I've had migraines with visual auras for as long as I can remember but about a year ago they started to decrease in frequency which is great. However, since then a multitude of other symptoms started occurring. First I developed a tremor in both of my hands which I saw a neurologist for. My neurologist diagnosed me with essential tremor after multiple tests and I accepted that. However, in addition to my newly developed tremor other things started to happen. For the past couple of months I've been experiencing a heaviness in my head that makes it hard to hold it up. When this happens my thoughts are clouded and I can't remember things to such an extent that I failed my bio class last semester because of an episode I had during the final. Additionally, theres a heaviness in my chest that makes it hard to take a complete breath. I am experiencing weakness in my arms as well and extreme fatigue during these episodes. I've had my copper levels and thyroid checked among other things, but have never had an MRI.