You're doing a great job finding inexpensive groceries in NYC if you are only spending $7-8 / day! Go you!
When I lived there 8 years ago, I was so frustrated by how expensive Food Emporium was compared to any regular grocery store in the rest of the country.... It made me nuts! Gristedes only very slightly better and a significantly longer walk for me, so challenging if I was "stocking up" at all or buying anything frozen or liquid.
Its more doing all the cooking myself. Eggs/oatmeal for breakfast, chicken/potato for lunch, lentil soup/veggies, assorted other carb for dinner + small snacks throughout the day. Its actually fairly easy. I could probably cut it down a touch more price-wise if I went to specific stores for specific food items, but there is only so 'crazy' I can go. The main point is that you can fall prey to taking the 'easy' way out and spend $20+ a day on food and then wonder why you can'y afford x/y, or you can do it on your own and truly control costs much in the same way you can do your best to control rate of savings. Most other things are out of our control which is why reserves are important to weather the situations in life that come from 'nowhere' to affect us.
In my example, learning to cook even 1/2 way decently and actually having the mental fortitude to do so on a regular basis will literally save you thousands each year. I just have this Seamless ad campaign in my face every AM subway commute and it annoys me knowing that its likely very successful while at the same time dooming many to extra years behind a desk because they pawn off something super easy to do for the quick fix.
