I would have believe this if this is a fantasy manhwa, but it is not. Cain, you appearing makes it even more stressful and frustrating than it is already. And all because you "REMEMBERED" that you're a dog in your past life? Dear Cain, just because you remembered that you're a dog in your past life doesn't mean it actually happened or means it's true. People remember things a lot that actually didn't happen because they wish it did or because they thought it happened, like you. It might have been a creation of your imagination and when you saw Jooin, you might have think that he is that person. Don't be delusional. Try seeking the help your parents asks you too, just try it. Just like you said, they don't need to believe your a dog in your past life. You also don't need to believe what the doctore would say, just listen. It won't hurt you. And you can't blame Jooin if he doesn't trusts you, you also don't trust him enough to tell him that you're the only one that believes you're a dog before.