I've seen a psychodynamic therapist privately for years. I'm also ironically a mental health nurse! The modality is a bit 'blank slate' because it's all about playing out patterns in your relationships by projecting on to your therapist. The aim is to recognise your unconscious beliefs/thought patterns and how these relate to our past and continue to impact us in the present.
This kind of therapy is challenging and uncomfortable at times. I have an excellent relationship with my therapist, but I've known her like 8 years now, and we've definitely had a lot of ruptured and repairs (due to my own transferance). I've felt all kinds of feelings towards her: anger, love, a longing to be mothered, indifference. It's been hard, but it's the best therapy I've ever had. My therapist also holds absolute unconditional compassion towards whatever crap I tell her, and that's been more healing than I can say. It will make you truly do a deep dive into why you are the way you are. It might be that that feels unsettling right now, so really do some soul searching and ask yourself if deep down you're actually feeling frightened and question whether you have some defenses up. He may genuinely not be a good fit for you, but I'm not sure you could know after 3 sessions.
And in all honesty I'd tell him how you feel. If he's a good therapist, he will openly have that chat, as that's what this kind of therapy is all about. I've told my therapist before when I've felt mad at her, or if something isn't working, or I can't read her, and we've talked it though. If you think he looks confused, ask him. If you say you don't feel you're a good fit, tell him. You will definitely be met with a lot of 'it's interesting that you're seeing my face as blank right now, I wonder why you might think that', but that's okay.
It's a very open ended and client led therapy. It ultimately might not be for you, but my advice would be to stick with it for now. I know it feels weird to tell a professional you think they look blank or confused or whatever, but I promise you that in this form of therapy it's very welcome.