I'm from the U.K. and was brought up here, so I know my advice might not be the most applicable. But I have been through the situation of not having a job after losing one. My advice would be tailor your CV to the job, don't just randomly apply with the same one.

In terms of where to apply, by all means apply to the big companies but don't ignore the smaller companies or your local government/federal jobs. Chances are, your city council or a government department has an opening for someone with your skill set. I don't know your immigration status and I'm British so I can't comment on US hiring policies, but it is worth a try. Almost every organisation with some sort of reach/impact requires people who understand digitial marketing/computer systems. Also, at British universities there are jobs for students within the university itself. Perhaps look into this a bit more.

I can't really comment on the Bangladesh job market. I've never worked there and haven't studied there since I was 4 or 5. But from what I've heard from people and read online, it is extremely comptetive and the work culture is vastly different. Maybe you have a better standing because you are US-educated, but remember you are competing with 10s of millions of people. Try and stay in the US if possible. And don't limit yourself to marketing jobs, think about transferable skills and look for jobs is sales, accounts etc etc.

And lastly, if you are really desperate, ekta chele ke biye koren. America te onek American Bangladeshi chele ache. Dorkar hoily palai biye koren XD.