Many commuters in your situation simply lengthen their commute route. I used to ride with a woman who commuted 50k round trip every day. She lost 50 lbs. in a year of doing that and got quite fast.

Don't worry about your blood sugar issues. I assume you mean hypoglycemia. It won't raise it's head on the bike, and riding will to a large extent make it go away in your civilian life too. Your riding metabolism is different from your off-bike metabolism. You can eat straight sugar on the bike and never crash as long as you keep it coming. You don't gain weight as long as you only eat about 1/2 your burn. The whole idea is to keep your blood sugar up on the bike. One way to do that, oddly enough, is to eat nothing on a ride of 2 hours or less. Your body is just a chemical factory. You can modify the factory's processes with your inputs. That's mostly what training does. So by eating nothing, you encourage fat burn, which can take the place of eaten food if you keep the effort down.

So if you want or need to eat, like on a long hard ride for instance, it's usually best to start eating a little at a time early in the ride and just keep up a steady intake for the duration of the ride. A variety of carb-high foods work: sports drinks, dried fruit, sports bars, gels, shot bloks, all sorts of stuff. The main thing is to eat only a little at a time and eat often. Eating to hunger usually works well.

I've never seen a rider bonk on a ride shorter than ~100K and one would have to be riding hard to bonk even at that distance. What you might get is a little spate of low blood sugar after you've burned off your initial blood sugar and your fat burn hasn't really started yet. Many people notice that after 45 minutes to an hour. If that happens to me, I just ride through it and feel fine in a few more minutes. If I don't, there's always food in my pocket or bottle.

Riding long distance is all about problem solving. That's really all there is to it other than some initial conditioning. It could be that your achy feeling is lack of calories or water. You might try eating and drinking more when that starts and see what happens.

If your goal is to ride a double metric, you need to ride that distance or more per week for several weeks prior. You'll also need to do a couple of long rides of over 100k to get the idea of eating and drinking on a schedule or at need and also to test your butt at longer distances. You'll want to stand more often, for instance. Or you may find some source of saddle discomfort that needs to go away. Riding a fast double metric is another animal that needs different training than simply going the distance.