If I was in your shoes I would sell the appartment at a loss to what your remaining mortgage is, if you have to take 20,30,40k hit then I would as I could balance it out via the inheritence. You would still have a good lump sum in the bank afterwards.
My reason to do this would be based on my opinion on where prices of appartments are headed and my belief that it will take many years to see an upturn again in prices. I also wouldn't want the hassle of being a landlord but if you work out the figures would it be worth you renting out the appartment? (edit: sorry, I see you have done and it means you have to back it by 300 per month. If you can't rent it out for a month or two then thats a big hit to you.)
I would rent in the meantime before looking to purchase a house again after price drops in property have stopped.
Thats what I would do anyways.