Adjectives ending with 'ed' or 'ing' are derived from a verb. 'I am bored' -'Bored' here comes from 'to bore' in the passive voice 'I am boring' -'Boring' here comes from the present continuous form of 'to bore'. So something that is boring is the subject of 'to bore', while something that is bored is the object of 'to bore'. 'Boring' and 'bored' are so common that they have become adjectives, and can be used as such (ex. "a boring person"). However if you want to figure out what they mean, you just need to know the original verb and how to use the passive voice and present continuous.

"I'm bored" is a feeling. Something else bores you. "I'm boring" means you are dull company. You make other people feel bored.

"I'm bored" is an action because you are *being bored* by the lack of interesting surroundings/activities. "I'm boring" can mean that you are an uninteresting person (as in, it's an adjective). It can also be an unfinished sentence with an action: "I'm boring [him]."