"I agree, until you said something I slightly don't agree with

Yeah, that's kind of how agreeing and disagreeing works..

Now you're a xenophobic racist and I disagree with you completely."

Nah, what I (correctly) pointed out was that one sentence was xenophobic. I didn't say that it was necessarily representative of you as a person or that it made me disagree with the things I agreed with before.

I said that I didn't like your comment anymore because it ended with a xenophobic sentence. There's nothing odd about that. Seems I'm not the fragile person who needs to grow up here.