This is a problem for all expats, how often do we see a new car for sale, owner leaving Qatar, I bought a car from someone (at a slight discount, maybe 5%) who was leaving Qatar within 2 days! What would he have done if I didn't buy? He was lucky, made a deal and I stuck to it. Even so he paid the bank back maybe 14000 QR more than I paid him, despite having made 15months payments on the car!
Same for a house, u make a deal and if u leave now the owner must suffer interruption in payment waiting for a new tenant and probably a reduced rent now because of a falling market! Why should he lose on an agreed contract. You will be lucky if he accepts, why should he lose because u are terminated? and in Qatar he can stop u leaving if he is likely to make a loss!
Best thing explain ur situation, say u appreciate his position and give some gesture towards his loss. If you can, find someone to take over the tenancy. Again u may lose if they offer a lower rent. Good luck!