There's a small logical issue.
Mr. Bad Guy rules the world and has 4 magical dragons. You defeated him. Assuming that Mr. Bad Guy didn't slip and fall into his sword, this implies that either you alone are stronger than Bad Guy and his dragons (then why didn't you kill the dragons, and why would they follow you now?) or the dragons turned against their master, and you and them together are stronger than Mr. Bad Guy.
However, in either case, either you alone,or you plus dragons are now the most powerful entity in the world. If that wasn't the case, Mr. Bad Guy would have been superseded long ago. Therefore, the question "can you make it home safely" is already answered before you start.
Now, one could imagine that in order to "restore the balance of nature" (or some similar story), it is necessary to bring the four dragons to the four corners of the world, but the dragons don't want that, for some reason. This would explain why you didn't kill them (it's necessary that they're alive), and why travelling is troublesome and risky (since it's not you and the dragons against the world, but rather you against the dragons and the world).