I live in London and haven't even seen the episode where Nupur dies. I came online one day because I had missed an episode and wanted to read the update. I was shocked when I read that Nupur might die (just might). The accident hadn't happened yet and fans were just discussing the possibilities. I cried all night and couldn't sleep for days😭. When I read that it was confirmed that she died, I stopped watching MJHT even though were behind here and hadn't even gotten to that part yet. For me, there is no point in going through the tunnel that is MJHT if there is no light at the end (light = Nupur & Mayank ~ Together forever). Nupur & Mayank are the heart and soul of the show. Without them there is no MJHT for me.
You are not alone in how you feel. Even as I write this now I can feel the loss of Nupur and I haven't even seen it yet! I also agree that maybe this immense attachment to a fictional character isn't healthy, but then again even psychiatrists have said that the death of a fictional character you watch often and care for can feel like the death of a family member or friend. I am now watching season 1 from the beginning, (ignoring Nupur's imminent death). I have hope that very soon I will hear the good news that Rati is returning to MJHT, that too as Nupur.
Here's hoping that we all feel better soon!