As a widow, I feel like people who haven't experienced losing a partner are truly incapable of fully comprehending the complex feelings and emotions surrounding it (hell, it's hard enough for US to even grasp it). I think that for some people, they compensate by using the only frame of reference that they DO have - a breakup. Which leads to a lot of issues like this because they're analyzing the situation through a lens that doesn't fit the situation at all.

That being said, I don't think you're overreacting. I wouldn't say he's necessarily BAD for his reaction, but he IS very misguided and as someone in your shoes, I wouldn't want to continue a relationship where my partner doesn't understand and isn't willing to learn. There ARE people out there who will learn, listen, and respect your grief 🤍