Stay aware of how you feel now, including energy level and emotional brightness, and once you start on insulin. Many report feeling a positive effect immediately.
You are right to be wary of insulin; it is our most powerful tool and it deserves respect. Used well, it can change your life for the better. You will need to learn a few things about insulin, like your insulin to carb ratio (for mealtimes) and insulin sensitivity factor (for high corrections). Knowledge makes a key difference in how we do with insulin. Take any course or training offered. Start looking at at good instructional book like Think Like a Pancreas by Scheiner.
Do you know if your docs intend to start you on long-acting insulin first before adding short-acting for meals? In any case, consider this your time to bone up on everything you can learn about insulin. It may seem complicated at first but it is not rocket science. Take your time learning a little each day. Some things need a few days to finally sink into your brain, so pace yourself but spend some time every day learning.
I highly recommend that you start a log and record your food, insulin, exercise, and blood glucose tests. Have you received a glucose meter yet? Follow your numbers closely and it will pay you great dividends. That means you need to test more in the beginning while you're learning insulin's effects.
Your meter will also inform you how to eat. If you make a practice of testing before and after every meal, then you will learn what foods are OK, what foods to minimize, and perhaps what foods to consider dropping. "Eating to your meter" is a highly successful tactic that has stood the test of time. Watch your meter and it will guide you toward good decisions. The numbers don't lie.
And don't be thinking that this time in your life is all about taking away some of your favorite foods. If you're honest with yourself you will be able to learn many new favorite foods. Many of us limit the number of carbohydrates we eat. Meats, fish, cheese, heavy cream, nuts, a hearty array of vegetables, and berries are part of what we like to eat. Everyone is different in food preferences but I guarantee you that you can discover a satisfying way of eating that will satiate and leave you with good glucose numbers, too.