I think you are right and that it won't be horrible but their agricultural sector will face a hard time with a more plateau-centered territory and they likely lost a rather descent chunk of their industrial and whatever service sector and trade centers they had. These can always be rebuilt with foreign aid, especially the latter, but it's still going to hurt a lot and the damages will be hard to fully repair, especially since they faced similar blows in the aftermath of the Balkans Wars and WWII-Greco-Turkish War. Hell, if anything these were probably even more costly in the grand scheme of things but the Ottoman state of the time was better able to absorb them then it probably will with this round of territorial looses... There is always the mining sector, which will be less damaged by whatever peace terms end up being given, but even there you'll have key deposits falling into the hands of the Kurds and the Soviets, and in the latter case they are likely to pass to Georgia and Armenia for the most part if the USSR also end up collapsing ITTL...I think we will see a significantly larger diaspora as you say, that’s likely a natural outcome. I imagine they’d likely take the space of what is likely a significantly smaller Greek diaspora ITTL.
That being said I don’t think Turkeys economy will be in that bad a shape by the mid to late 50’s. At least if they aren’t a Soviet puppet which is possible. If they’re neutral or Western aligned I see no reason why they wouldn’t experience a large economic boom from the Marshall plan post war like the other major participants.
Overall Turkey is going to have a pretty though time. There is just no way around it for a state that took three major beatings in three decades and didn't get a parachute in terms of territorial looses in any of those, sadly for the Turks civilians.