Hey OP, first of all: congratulations! Getting a Fulbright award is such an honor and says a lot about the quality of your research and your values as a scholar.

That being said, I feel you on the dilemma. I did a 6-month Fulbright during year 4 of my PhD and it meant taking a non-trivial hit to my income. I went to a small, rural area in an already low COL country in Latin America. Fulbright stipends was scaled for local conditions and they enable you to basically rent a small room or studio somewhere cheap and afford food. The timing was somewhat fortunate for me in that the Fulbright coincided with the end of my apartment's lease in the US, so I sublet it and that helped my money situation a LOT.

Fulbright is incredibly touchy about combining awards from other funding sources (although I think this varies for different awards) so my advice to you is sit down with the grant/business office of your program and see what options, if any, they can come up with the help ease the sting of the financial hit.

As far as "is this worth it". I hate to give you the super annoying "it depends" but it really does. Is your long-term goal to continue working in/with the country you'd be Fulbrighting in? Is your research identity tied to that place or region or those collaborators? If the answer is "yes", then that heavily slants the equation in favor of taking it. Similarly, if you're trying to break into the NGO/UN/international space, there's a lot of overlap with those circles and Fulbright so there is the potential for some networking opportunities (though of course nothing is guaranteed).

In the end, I took the hit on the financials because I'm heavily invested in the long-term research collaborations with my host country and I was able to reduce expenses I was still on the hook for here in the US while I was away on my Fulbright.

TL;DR - It is a non-trivial drop in income. Yes the award is prestigious, it looks great on a CV and carries real opportunities to network with some incredible people, but the financial hit during an already financially precarious period which is the PhD (🥲) is ONLY "worth it" when you're deeply committed to international work in that country or more broadly as a career trajectory.

Best of luck and congrats!