I'll give you an example. In Looper, the kid was supposed to grow up to become the Rainmaker in the future. That's why Bruce Willis' character went back in time to kill him as a child. No matter what he did the kid became the Rainmaker. Bruce was going to always try to kill the kid, and end up, by accident killing the mom, which causes the kid to grow hateful and force him towards that future. No matter what he did, that was the outcome.
Your question is....how did the kid become the Rainmaker the first time? Before Bruce went back. The only thing that was holding him back from becoming a monster was his mother getting killed, so in the first timeline, she could have died any number of ways. It didn't have to be Bruce that killed her. He was just the one doing it in his timeline. So he killed himself to stop himself from hurting the mom. The other timelines/universes are irrelevant because each timeline/universes is separate.
So let's say Hodor was completely normal in the first timeline. A regular dude. Bran still falls off the castle. He finds some other way to get to Bloodraven. He jumps through time, screws up Hodor's head by accident. Now the Bran in that timeline will grow up with Hodor, creating the loop.