Tamas usually have a bit of "wiggle room" when it comes to evolution, so you should probably just wait a bit longer. I'm not too sure what the range is on the Demon Slayer Tama, though; hoped this helped regardless!
I do. I was the only one in school with a connection, and since none of my friends had one, I got an oldie, which I didn't like. It died one day when I was swamped with homework...I still felt really guilty.