I know this was several years ago, I hope you found the right dose of meds and life got easier. I had my Thyroidectomy 4 months ago and feel the same way. I feel like I'm going to pass out sometimes too, which is loads of fun when I'm driving. My life went from normal to hyperthyroid storm symptoms and barely being able to function, to having surgery and playing the let's adjust your meds and wait every six weeks to see if it is the right dose game. Meanwhile my slew of symptoms like brain fog, constantly between insomnia and fatigue, the hot flushes, the feeling faint, the sometimes difficulty catching my breath, just feeling off inside out, the head in the top of my head. This is my new normal and I honestly think to myself, "this is what a slow death feels like." Modern medicine in all its wonder can't seem to fix it so I can level and supplememt my absentee thyroid hormones properly. No doctor seems properly trained to recognize the symptoms and look beyond a lab report.