I got a pair of male gerbils over a year ago and one just died today 😭 not sure exactly why but I know with rodents these things happen and there isn't much that can be done.

But I now have just one gerbil, from what I have read the other gerbil probably won't live long on his own. This is my first time with gerbils and I'm just wondering what to do. I'd gladly get another gerbil but I cant find anywhere that has them. Is there any way I can keep the surviving gerbil happy?