Sounds like you have passed selection and have been offered a joining date, etc. I would just politely delay your join date until you have clarity over command back home and what you want. If you cant make a decision then dont feel forced to make one you might ultimately regret either way. I was close to command in my home airline and left for the 777. 5 years later I had to turn down a T7 command to go home for family reasons, starting all over again as 2 stripe FO with nearly 10,000 hours. Plan for the unexpected....
If you are in a reasonably stable secure airline with the command prospect I would personally see that through, given that the rapid expansion in the ME3 is finished for now and there is no immediate rush to join a seniority list there. I doubt I would have coped with being in Dubai age 26, but everyone is different.