By “insulin” do you mean Lantus? If that’s the case, your insulin is NOT covering your meals, just your fasting state. If cutting the carbs while on Lantus still doesn’t get your blood sugar to normal (which it did NOT do for me until I was hypoing at night from too much Lantus), you might want to talk to your doctor about using a meal time insulin like Novolog.
As far as exercising on a low carb regimen, goes it’s something I did for a year. You will probably find your blood sugar dropping some when you do aerobic exercise, and you may feel low, but since you are so high to start with, you probably are not low at all. Test your blood sugar if you aren’t sure.
If it is a “false hypo” i.e. 80s or highter, you really just have to sit through it and let your body get used to feeling normal. After a few weeks of being at more normal blood sugars, you get used to it and you will feel a lot better. Then you will also feel sick as a dog when you are at your old “normal” high blood sugars!
So you probably don’t need to treat anything while exercising until you get into the 70s. Then one or two Sweetarts (the hard kind) is all it takes to kick you up 10 mg/dl or so. I used to take 1 hard Sweetart disc ever 15 minutes while on the treadmill.
Protein gives you long lasting energy, so there is no reason to load up with food right before exercising if you are eating a lot of protein.
FWIW, my son was on a top Div IAA college football team where the team nutritionist was high on low carb body building and did NOT encourage the team to carb load. Instead, he urged them to eat mostly meat and vegetables and avoid sugars and starch except right before the game. I was so pleased by this, as my son had made it on the team by doing all his strength training and body building on whey protein powder and peanut butter.
In fact, that might be a good approach for you. Whey protein powder (NOT soy!) and natural peanut butter without the hydrogentated oils. All that protein goes right to the muscles after you exercise.
You can also make homemade protein bars with whet protein powder and peanut butter. Roll them in nuts to keep them from sticking. No nasty additives or soy!