Just on a quick study, I kind of think the hypokalemic periodic paralysis could still be an issue, and there's a way to make it stop if this is true. Next time you get an attack, as soon as you can, eat a whole banana for the potassium. According to some medical literature, the way to confirm a clinical diagnosis of HPP is give potassium during an attack to see if it stops the numbness etc. It's a "natural" and handy way to get it in your body, so you don't have to rush to see a doc for him to check it and give it to you. And if it stops your attack, this is good, becuz treatment is designed to prevent that fluctuation in potassium. Also, in general, avoid heavy, high-carb meals and too much salt. You shouldn't be eating bananas wall-to-wall. Just eat one when you have the attack (or I guess maybe two, depending on what happens).
And the sensitivity to sounds is a ringer for magnesium deficiency. Just google search: "Hyperacusis + Magnesium".
The fact that you have had low potassium tells me it's most likely your electrolytes (Magnesium, Potassium, Calcium, Sodium). Though your blood levels may not look severe, it doesn't say what your tissue levels look like -- probably very drained.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2146789/pdf/canfamphys00077-0094.pdf
Testing:
http://www.medhelp.org/user_journals/show/230120/Magnesium-Testing?personal_page_id=1012978
I think it would be wise to try a magnesium supplement, if your doctor says magnesium is fine for you.
Some of the safer and more effective forms of magnesium include: Taurate, Glycinate and Citrate (latter can be laxitative so take with food).