How to recover from someone who made you doubt everything and crushed you?

Before I met this person, I knew that I was on such a high frequency. I was floating, was so confident, didn't only believe but also felt the law.

I've met this one person and they crushed me. I don't know if they were just so negative that it took all my energy of if I wasn't really as healed and settled as I thought...

But how to recover from this? I am listening to Joseph Murphy's Audiobooks and will start The power of awareness soon but I'm afraid that it will take me a long time to get back to the state I was in before.. which is a pity since I am going to a new country soon and really don't want to feel like this when I'm there :/