The problem is America has been over marketed over the world for better life, job and security which is not true. You will soon realize it once you land in USA or if you do some deeper research on the Internet. America has lots of its own problems- there is high rate of unemployment (forget about government or Internet figures all are manipulated here to create rosy pictures). Yes, there are lots of modern slavery jobs (very low paying, dirty, dangerous and difficult- where you will not find any white guys working- such jobs you have already mentioned in your articles) Even for Americans with USA degree, it is hard to get a good job- furthermore students have huge study loans (loan -credits is big story here-- search Internet). There is lots of government rules for even small things (which effects your life in every moves). There is many forms of tax and all add up to huge (federal tax, state tax, medi-aid, etc) plus there are others premiums to pay every months( health care, mobile bills-very high cost compared to Asia, Car insurance and so many other) and are controlled by state. There is no free competition for the benefit of the consumer here. I read in business book that consumers are the king, but in America it is company is the King-you can post your comment below to prove it wrong with some examples for rest.
Furthermore to make the situation even worse- house rent is too high compared to what is your income(minimum wages jobs you have mentioned and it is controlled by the government/state too), that is why you will find lots of homeless people all over USA specially in big cities.
You must have read income gap between rich and poor Americans online and there are more discussion, going all over the the Internet. There are many other's issue too which I don't want to mention here, you can google it.
Not you have to work hard to survive here but you have to control yourself psychologically to avoid problems you have mentioned above. And biggest challenge is that everything (I mean everything...) you have to do your own, no one will help you here (even Nepalese-everyone have their own problems and everyone working hard to survive here- no time) which makes your life even harder.
I know everything sound negative but what to do this is reality here- may be you can post some positive points.
I know many people have left USA, but they also not tell you why they left which has misguided others.