Learning My Place in This Dynamic

I'm 28 and I recently started engaging in a dominant/submissive relationship. It's been both exhilarating and challenging, but I feel like there are times when the level of discipline feels over-the-top to me. We met online through an adult kink community and have been together for about three months now. From day one, it was clear that he's very strict. His demeanor is authoritative, and every interaction has a sense of hierarchy, I'm meant to be his submissively obedient companion in everything we do. At first, this dynamic felt empowering and exciting; however, as time passed, some situations have become more demanding and less playful. For example, one night after a disagreement about boundaries (which was my fault for being unclear), he disciplined me by making me stand against the wall with my hands behind my back for several hours. While this wasn't physically painful or abusive in any way, it's all consensual and I know he cares deeply about my well-being, it left me feeling quite humiliated and shaken. Another instance involved him punishing me by restricting my access to technology for a day, which in today’s world feels like an eternity of isolation. While this was discussed beforehand as part of our agreement and safety measures, the actual experience made me feel incredibly lonely and out-of-touch with reality. I value our relationship deeply and am willing to explore these boundaries further, but I'm starting to wonder if some of his actions cross a line for me personally. Is it common in D/s dynamics to have such stringent penalties, or is there room for adjustment? How do I communicate that while I enjoy this aspect of our relationship, maybe less extreme measures would feel more comfortable and enjoyable? In short, my question is: Am I overreacting here? Should I expect continued intense disciplinary actions as part of a D/s dynamic, or should I voice these concerns to him in hopes of finding common ground?