May I know what is the difference between I used to vs I'm used to? I have seen both of these words on various media. So please tell me?
See this duplicate question.
In short, used to refers to an action in the past which is not continued into the present, whereas I'm used to means that you have become accustomed to something.
"Use" means, well, what it means, incorporated an artifice, artifact, feature, function, etc. into an activity.
I used sour milk in the pancakes this morning.
An activity in which you have customarily or habitually engaged in the past is an activity that you have made use of. As I understand it, this is how the expression for "used to do" came into currency. A customary activity that you incorporate into (used in) your activities in the past is an activity that you have used.
It's common (but not guaranteed) to become accustomed to the things you do by habit. Thus, you have probably become used to the things you used to do. It's almost as if being used by a habit makes one accustomed to it. (Note that the form is nominally passive be+"used to".)