Looking for a term for this situation...

Where one person, (who uses their brain, who gives a shit, who has always tried their best in life, but is now in a crappy position in life due to burnout, anxiety and depression), has to help out another person, (who doesn't really use their brain, who has a carefree attitude, who didn't really work hard in life, but is now in a good position in life due to using their saved up energy on a couple of things that really mattered to them and stuff working out), with the sort of things that you would expect them to be able to now do themselves when you look at the position they are in life?

It's not a case of the blind leading the blind is it? Because that would imply equally disadvantaged people, with one just trying to help out the others the best they can.

Here it seems to be a case of, those with previously good eyesight who now have tired, red, crusty, sticky, watery eyes leading the traditionally short sighted in really sunny weather, who have somehow managed to bag themselves a pair of expensive sunglasses which makes them look cool to the rest of the world.

Is there a term for this? Where it's the capable person who is now in a messed up position that's helping out the less capable person who is now in a better position?

On a separate note, I suppose this is an example of the unfairness in life. Where those who have the potential to achieve something, work hard, but fail to do so. And some people just get lucky and achieve loads. And somehow it's the 'failures' that find themselves helping out the 'winners'.

If a person's position in society correlated directly to their work ethic, society would look very different indeed.

Any suggestions?

Not sure about a term but that person can be described as a "user" due to your description.

"Spawny Git"?

Hmm. Both are very apt descriptions indeed for this kind of behaviour.