Sorry, Anthony, I can't remember if you are on any drugs that can cause hypos? Normal people can feel the effects of low blood sugar and can go quite low - my husband certainly gets grumpy if he needs to eat! So you may well have felt low pre diagnosis. We are all different and have different symptoms, but the most common ones I would think are shaking, feeling hot and sweaty, some people feel really hungry, others don't. If you go lower then your brain starts to become effected and you might get angry, confused, disorientated, eyes might go blurry.
Hypers are more difficult to notice in my experience. If my blood sugar is over 10 ish I tend to feel sluggish and tired out. If it is high for a while it's like walking through treacle.