According to Urban Dictionary, the official origin of the little phrase comes from a fast-food commercial that aired in the 1980's, featuring a mentally handicapped employee saying, "I'm helping" despite his actual lack of help. In the real world, "I'm Helping" is applied in a similar way. Let's say for example, that you have a wasp hanging around your head.

Yeah, like this.

And your friend comes up to you wanting to shoo it away. He goes to smack the wasp… with his fist, bashing your skull in and giving you brain damage for life.

That's what he gets for sporting those ridiculous side burns.

This is a good example of "I'm Helping". When you are providing 'help' that is actually completely and utterly useless, pointless, or all around unhelpful. Now surely, everyone has been there. For example, you and a group of friends were supposed to create a poster for a presentation, and one of you were given the difficult task of 'holding the markers'. Somebody probably walked by, asked them what they were doing, and they shouted back "I'm helping!".

Ex:

On the show Sealab 2021, in the Bizarro episode, this phrase was used often.

This isn't a meme that is recent. In honesty, for all of my life I've used it without even realizing it could be recognized as such. Any time which you are being completely useless to society, you simply shout that you are helping, in hopes that nobody questions your methods.