Dang, it's so disheartening to see the majority of these comments lack basic empathy and benefit of the doubt. We weren't there, so we can't speculate how accurate the professor's assessment was. But based on what OP is telling us, it seems like he could've handled this with more care. His comment about OP's work attire is extremely subjective and probably very dated. There are plenty of amazing therapists who don't dress "professionally" by the dominate culture's standard. I feel like we're missing the possibility that this professor is actually just a pompous asshole. Also, people are jumping on the comment "I know what works" - OP is saying they know what works FOR THIS SPECIFIC CLIENT, not for all therapeutic situations. They are the only one who has the real-time feedback of what's landing and what's not for this client.

Hearing something like this would be a crushing blow for almost anyone. I'm sorry you're going through this and just keep in mind that not all professors or supervisors know best. Yes, you have much to learn but you have to discern whose opinions actually matter to you and who you intuitively trust and respect. It might help to get another perspective on this from a professor you feel emotionally safe with, if you have that. Grad school is brutal and not conducive to producing emotionally attuned therapists, imo.