Dreamed that my deceased grandma and dog came back to life.

So last night I had a dream that my mom, dad, sister and I went to visit my grandma (who actually raised me), and that she recently moved to another town. When we got there, she lived in a beautiful historical mansion but as we walked around we couldn’t even find her because it was so big. I started to feel really sad for her because she was probably lonely in this huge house. My childhood dog who passed a couple years ago was there as well, she was like 13 when she died. We eventually found her and chatted with her but it felt weird. I started to remember that my grandma died nearly 10 years ago. I mentioned to my mom that this wasn’t real and she got really angry with me and told me to shut it. I pulled my dad aside and asked if he realized that this wasn’t real, and grandma died in 2016. He told me he knew and realized after he noticed some “signs.” After he said this I looked down at the tattoo on my arm dedicated to my dog it looked as though I scratched it so much it was fading from my skin. That to me was the sign that things I knew in life were not the same in my dream. Super strange but it started to just become a dream I often have of running away from zombies in an abandoned building nearby, maybe because I wanted to watch the walking dead really bad last night lol. Does anyone have any insight on this dream ?

Some context: my aunt is a real estate agent and always tried to get my grandma to move away from us. I felt sad when I woke up but I mostly felt super weird. Like very off put because I knew something was strange.