I'm finished vs I finished [duplicate]

I wonder, what's the difference between I'm finished and I finished (or even I've finished)?

To be more specific:

I'm given = someone gives something to me

I'm told = someone tells something to me

I'm finished = NOT someone makes me finish BUT I have finished doing something.

Why?

I finished is more emphatic. It implies some sense of accomplishment, for example, if you feel proud of having finished an exam, or your seven-year-old has been struggling to finish his vegetables in order to get dessert. It means that something has been completed.

I'm finished is more matter of fact. "I'm finished with this book, you can read it now." It's synonymous with "I'm done."

"I finished" is more likely to have an exclamation point.

In practice, "I've finished" sounds just like "I finished" because the V runs into the F.