Usually people complain of low blood sugar as feeling shakey and nauseated. High blood sugar, you'll notice you're eating, drinking, and peeing more. Maybe it will edit that out. You'll go #1 more lol
Insulin is basically something the body makes, that takes the sugar in the blood, and basically "feeds" it to the cell. Once inside the cell, it no longer has any ill-effect. Your big meals, that would otherwise cause your sugar to rise, can be mediated with a shot before (which involves math, basically counting how many points each food is worth, then converting it to how much insulin you draw up into a syringe to give yourself.) Or~ you can be RE-active and let your sugar rise up, then take an appropriate amount based on your sliding scale provided by your doctor (Sliding scale is basically a gradually increasing amount of insulin for a gradually increasing amount of blood sugar, as with cutoff limits/parameters set by your doctor.)
Insulin is an everyday thing. Some people do shots with a kind of insulin that works all day. Others use the more conventional (at least to me) method of coverage that goes with every meal. People get VERY good at managing their sugar levels (I had a rotation at a middle school, and the kids with type1 were ridiculously fast with counting [carbs], preparing their syringe/insulin pen, giving their shots, and putting their supplies away.) I've seen a highschooler just start insulin therapy, and I've seen middleschoolers extremely proficient with their management.
Well, your question about the pills is something I really can't answer because I just dont know. That's definitely a question for your doctor. I'm curious as well. I know more about insulin, diet, and exercise when discussing control of blood sugar in diabetes, but less so about your metformin/glucophage.