Is it possible to buy an airline ticket that has me returning to my country after a year being abroad? I can't seem to book a flight that far in advance online.
Most airlines allow you to book up to exactly 12 months in advance.
This means you can buy a ticket where your outbound flight is today and your return (inbound) flight is exactly one year from today. Any other dates would be outside of this range. i.e. even an outbound flight tomorrow with an inbound flight of one year from tomorrow would be more than 12 months in advance.
One option you could try is to book a flexi-date fare that allows you to change the date of your flights with minimal charge.