Adjusting your diet and being active and lowing your weight are the better options to keep your blood sugar level down, rather than taking more and more medication. If you don't, then diabetes usually gets worse over time, so your medicine or dose may need to change. Insulin is not often used for type 2 diabetes in the early years. It's usually needed when other medicines no longer work.
It's not uncommon for type 2's, with IR to need higher and higher doses of insulin, for example, 300-400 Units. This creates a large variability in the laws of large numbers, which is difficult to manage, and causes weight gain. As a type 1 I take no more than 15 units a day. I only take it because my pancreas doesn't make any, and my life depends on it. It's not an easy option and its a very difficult drug to dose. You eat the same food and you need wildly different doses due to a multitude of factors such as hormones, stress, time of day, exercise, packaging CHO reading being out by 30%, fat content of your meal, insulin more than two weeks old, being towards the end of a vial, hot weather, injection sites etc etc. Injecting insulin means you lose your BS homeostasis and you can now fall below 3.5 mmol/l which is classified as a hypo and are dangerous, so you need to monitor your BS's constantly.