Sorry to hear about your health issues.
On that note, have your doctor or endocrinologist done any Thyroid tests? I ask because when I was having balance problems, heart palpitations (115-120 bpm resting heart rate which was initially diagnosed as Afib) and weight loss, the doctor did some tests (bloodwork and CT-scan) on my thyroid and my enzymes were off the roof. Once he gave me meds to lower my thyroid enzymes (T3, T4 and TSH), my balance problems and heart palpitations went away. I’m have also gained back the weight I lost plus some .