I would like to join @johnbishop in welcoming you to Mayo Connect. As John mentioned, we are not medical professionals, we just share from our own personal experiences. Many of us have had hard-to-diagnose problems and we are familiar with the intricacies of the human body and the difficulty of getting diagnosed for a rare or hard-to-diagnose problem. I think of problems like yours as a health discovery journey and this journey can take some time, so please be patient with the process and remember it is always your right (and duty to yourself) to get a second opinion.
The plethora of symptoms you have been having must be overwhelming at times. Have you seen a neurologist yet? That might be a good next step. You mentioned that you will be having an MRI soon, will the MRI be of the brain? So many of your symptoms could point to a neurological problem.
Will you keep in touch and provide updates along your journey to an answer?