If you want to stretch your dollar, there are lots of more affordable places to eat along 9th Ave . Much better value than anything closer to Times Square and GCT.
@Saregama recently reviewed the Thai place (Lum Lum) that took over Pam Real Thai, at 49th (iirc) &9th Ave [NYC] LumLum Thai Seafood Bar (9th Ave)
I had a good Brazilian brunch at Samba Kitchen on my last trip (2019). Daphne is a fairly affordable Greek restaurant near your hotel.
Taxis are pretty cheap relative to other cities, so I wouldn’t hesitate to jump into a cab to Chelsea or the UWS to get a better meal for less money.
I’ve visited NYC after knee surgery before, and I survived! 
The cross town blocks are a pain in the butt- since they’re wider than the north south blocks are long. There is a crosstown bus on 42nd if you want to save your energy. But if I was staying on 8th Ave, I’d be taking a taxi or subway north or south for less touristic grub.
