• [myth] Insulin is habit forming, so you become dependent on it

No, it is not. Just because it is an injection it is not habit forming. It is a natural hormone.

If insulin was started because oral medicines are not working then it has to be continued to keep the blood sugar under control.

Insulin is not habit forming. It's just that the body may not be producing enough insulin and we need to give it from outside.

Also see earlier question - [myth] Once insulin is started it has to be taken life long