Your symptoms sound more like they are from the hypothyroidism. How to address this will depend a lot on the cause of the hypothyroidism though.
It would not be from a lack of epinephrine (adrenaline). Lack of acetylcholine could contribute to the memory and focus problems though. Lecithin granules are good for this as is trimethylglycine (TMG), which is derived from beet leaves.