@ Yeap - I've also thought about that, and since I haven't done that so what I've thought is purely objective.
While most of what was mentioned by Bigrekoketto were true, yet if you're determined and want to do good then those things will become secondary.
Certainly if you return to Nepal with high hopes then you will be disappointed due to the lack of infrastructure, and also the difference in culture there. But since most of us grew up over there, so I think the initial intertia will be overcome sooner than later. Especially if you become busy and focus on the positive then life will become normal. Beside if you're planning to get settle down then you will have added support system.
Having said that, try to think about your options. I don't know what's your situation here in the US.