An MBA in the US coming from a developing country usually comes with a long term commitment to stay in other countries to repay that loan. It is absolutely true that the US in particular has this added complexity that even if you make that commitment, you might not even get to stay for extrinsic factors.
But leaving that aside, the question would be what other options do you have.
- Darden is a T15 school in the US, so it should allow you to apply to good jobs, stay in the US for 3 years and if the worst happens you'd still have the brand to make a move to high paying countries (Canada, SGP come to mind)
- You've been WA at Darden, so it's not clear that you'll get into another highly ranked school with a scholarship. It's not impossible, and it def might happen (some people get admitted with scholarship at HSW and dinged at other schools), but logic would point out to that conclusion.
- If you start going down the list of schools, you might get a scholarship but it might hurt your chances of getting a good job / STEM visa, etc.
Knowing more about what you're aiming for in terms of post MBA job/earning potential might be useful. If you want to do IB/MC Darden is a great choice, you can get a job in the US and if the H1B doesn't work you can ask for a transfer to Canada/SGP or wherever you want to go (more for MC in this case). If you want to do NGO/social impact then the scholarship becomes much more important so it might be worth giving that a shot.
Lastly, I'd consider speaking to an admissions consultant. Some have knowledge on who's giving scholarships, and all of them have the knowledge to know whether your profile fits those schools.
Sorry if I'm not being clear on which direction to choose, but I completely empathize with the fact that looking at a 250k loan seems scary. If you do go the debt path, it will help you to maximize the value of the MBA and do everything necessary to get yourself out of that situation, and after that your earning potential will have grown considerably.
Good luck!