How can I know whether to use had or have?

how can I know whether to use had or have?

Is the text correct or should the highlighted words be replaced by had?

It made sense when he said that, that the guilt I felt earlier was built on a nonsense. "If I didn't do that, then this wouldn't happen." Leo thought he shouldn't have insisted that much when I told him not to bring me, because that'd mean I would have never run away, then he wouldn't have come after me. Actually, this went way back Jason, who invited him, because if he hadn't, then Leo he wouldn't have brought me, I wouldn't have run away and he wouldn't have come after me. Of course, Jason wouldn't have invited Leo if Sophia didn’t decide to throw a party, because if she didn't come up with a party and told Jason to invite everyone, he wouldn't have invited Leo. And it's not really Sophia's fault that the football team won; given that that was the only condition in which she'd throw the party, and it's not the team's fault that they won, it's their rival's for being weaker. That line of thought follows without a defined place of start, and if anyone went far enough with it, the guilt would always be found on a different person until it reached the creation of earth. This cycle would go on and on and make less sense each time.