Saga Luke & Obi Wan Dealing with Failure

Both Obi Wan and Luke had failed stidents that caused great harm to the Galaxy.
Yet Obi Wan seemed to remain much more emotionaly stable in the years following Anakins turn to become Vader than Luke did after Bens fall.
IMO Much of this had to do with Obi Wan have had spending virtualy his whole life at the Temple and absorbing the Jedi mindset in a very direct way..
Luke had a very late start and shortened training without the benefit of the day to day interaction and environment provided by the Temple. While remaining optimistic about his father, Luke tended to be impatient and unsure about his own abilities. His failure at the Dark side tree, his failure to move his x wing from the swamp and disbelief at Yoda being able to and his questions about his own ability to carry on after Yodas death are some examples.
Luke certainly made progress with this as he became a Jedi but these doughs and emotions would have come crashing down on him once he almost kulled his nephew in a moment of Darkness.
Obi Wan also had the benefit of reconnecting with Qui gon in his exile to help stabilize his emotional state.
Luke knrw from history what his failure would mean to the galaxy while Obi Wan had years to absorb the events between ROTS and ANH and his training with Qui gon to prepare for what lie ahaed.

 

I hate what the ST did to Luke's character

 

I think the big difference between Obi-Wan and Luke dealing with their failure is that Obi-Wan had hope in the form of Luke and Leia as well as having the spirit of Qui-Gon to talk to for guidance.

In contrast Luke had no hope and believed that it was all his fault that Ben turned (personally I don't think it was since from the way I interpreted things, Ben was already a dark and screwed up kid anyway through no fault of his parents or Luke but that's up for debate I guess) compounded by his distraught at his nephew destroying everything he had worked so hard to build and knowing how devastated Han and Leia were about it that broke him.

Another big thing as well is that because of him closing himself off from the Force, Yoda was unable to give him much the guidance he needed until he opened himself to it again after watching Rey use it.

This is a thing that I really like about TLJ. Rey came to Luke looking for help and guidance but it was ultimately her that helped set him onto his path of redemption he so desperately needed, even if she didn't realize it herself.

 

I don't think Obi Wan really failed... he did his best with Anakin and while he may have been a little close minded and pompous, he tried his best and never turned on Anakin the way Luke turned on Ben Solo. I agree that his background was an influence, though by all evidence he did blame himself for Anakin's fall. I guess Obi Wan's biggest failure was not sensing the darkness in Anakin ahead of time, while Luke apparently sensed Ben's darkness early on (likely influenced by his grandfather).

Luke probably did jump the gun when he came close to killing his nephew, though I can think of an explanation (its just mine though, nobody has to treat it as fact). He had worked and risked everything to redeem his father Anakin, who had returned from the dark side to sacrifice himself and fulfill the prophecy. Luke may have been afraid that if Snoke got ahold of Ben, what Anakin had done may have unraveled. Yes, as @Grievousdude said, Luke didn't have as much Jedi background as Obi Wan did, and he was more emotionally vulnerable because of his ties to both Anakin and Ben.
He did see his mistake, assuming the last flashback was true, albeit too late.

Like Obi Wan, Luke maybe could have acted sooner and less drastically, but both Anakin and Ben made the most pivotal decisions by choosing the dark side.