As long as you're on fixed doses, I would try to live as regularly as possible. However, the basal/bolus regime which you are on is designed to enable us to live irregular lives. I think you best learn to carb-count to adjust your insulin to different meals and different days. See if they offer some course in your area. As you'll get better at that and more confident about making decisions regarding your insulin/food/exercise you'll be able to dose for what you'll eat at the time you want to eat. The only way to learn this is to use A LOT of test strips, or a Libre/GCM (which I use).
For instance, I was at a bbq party yesterday and had the following injections: 1. I fancied a small piece of baguette and injected for that. 2. Five minutes later I decided I wanted a beer after all, so injected for that. Ate salad and stuff from bbq. 3. an hour later I saw I was going up much faster than I expected, although still in range, figured I had eaten some hidden carbs, so I took a correction. 4. Saw it was going down faster than I expected (must have been to eager to correct) so had a very small bite of birthday cake. Tasted real good, so decided to be naughty and eat a full half slice and injected for that. 5. Went home, dropped slowly on the way back but started to rise an hour later. Took a correction.
(WARNING: Don't try to pull tricks like this until you know way more about how your body reacts to food and insulin! It could land you in very nasty places. I only told you to let you know it's very well possible to live an irregular life on insulin)
Now the above is a bit extreme, and I usually have only one injection per meal, but it shows it's perfectly possible to eat and inject more often than once every 4 hours. The problem with that is that you have to take in account the insulin still going around in your body to prevent going low. You don't learn that in a week.
Good luck, and nag your nurse about a course! Do you know if she has many patients on mealtime/long-acting insulin? It could very well be she's a bit out of her depth with it, and therefore reluctant to support you in finding your insulin to carbs ratio's. Much easier to tell your patients to eat the same amount of carbs at the same time with the same insulin of course. It's what diabetics did for years when everyone was on mixed insulin. That mixed inulin regime is why so many people, including HCP's think diabetics need to live very regular, boring lives.