Despite I'd like to see one day a TL with a Greek victory in the war of 1919-22 which allows Hellenic suzerainty over Istanbul/Constantinople, sadly this is not this one. Too basic historical concepts were ignored, and went far away into ASB. I am not so critic towards a TL generally, but this time I felt the necessity to express a disapproval.
Said that, I don't want to demoralize you. I guess this is your first attempt so mistakes are inevitable after all. I suggest you to curb down the really implausible parts which you developed so far, work over a more small empire in a more OTL scenario, not push immediately in terms of decades, and to seek over the possibilities where this country could effectively expand reasonably, not necessarily in terms of military expansion, but also over economic and cultural ones...