Black and white thinking is common in borderline personality disorder, which depression is also common in. You could inquire about that.

If your only complaint though is depression, then you probably do have depression. If you weren't aware of your black and white thinking, then it's probably not too much of a problem for you. It's a problem where your black and white thinking interfere with your interpersonal abilities. If that sounds like you, then you should definitely ask your T about BPD.

I hope everything turns out alright!