I started a new job at the beginning of the new year, and at first, one of my coworkers seemed friendly and I thought he was genuinely trying to help me out because I was new, but now, I believe he is actually toxic.

Before the quarantine, we would have meetings to discuss ideas for projects. While he claimed to be "trying to help me" and held the meeting to discuss ideas, whenever I had an idea that I pitched to him, he didn't like it and would instead explain why his ideas were better.

Later on, when I asked him what he thought about something, he took one of my previous ideas and claimed it as his own.

He wants to hold these meetings under the guise of "helping me out," but always finds ways to tear me down and assert his opinions over mine. After he criticizes me, he steps back by saying "I'm not trying to criticize you," or "I'm not judging you."

I regret becoming friends with this person. What should I do?