Going to study PhD abroad with weak economic backing?
Many (most?) doctoral students in the US work as Teaching or Research assistants. The stipend, while small by the standards of regular employment is enough to live on nearly everywhere. There isn't money for extras but a couple can get by. When I studied, the stipend was about 1/3 to 1/4 of the starting faculty salary. I think that it is similar now. Explore this with any US doctoral institution. 

There may be visa restrictions for some students and in some situations US citizenship may be required. But I think the visa problem would be especially severe for anyone from Iran now, due to geopolitical considerations. Hopefully these will ease but probably not for a few years, at least.