A couple of things, @Sara1277 . You booked the place knowing the cancellation policy was strict, so it makes sense to just take the 50%.
Have you looked at your own travel insurance to see whether this is covered? I don't know how that works when it comes to job relocations.
You could ask the host whether they might consider refunding you any nights they manage to rebook. As it is seven months out, depending on where you are going, the host may be in a position to agree. Hosts do choose the cancellation policies that they require in order to run their business, though, so it's not a given. No harm asking nicely. I wouldn't make it an argument.