We lived on one income for much of the time that my kids were young. the kids are teens now and we live one SSDI (read: not much at all) and my part-time salary (also not much). Our income is below the poverty line, so i hear you loud and clear. We never even had cable until about 6 years ago. I still plant a garden every summer and can the veggies from it for later. We eat about 1/4 of the meat that most families do and we have vegetarian meals quite often. Eggs are cheap and nutritious. I am a whiz with soups, beans and rice. I buy almost no pre-prepared meals, no frozen dinners, and very little food that is processed. Most of our fruits & veggies are in season.I don't buy junk food, soft drinks, or desserts except on specific occasions. My one bow to luxury is feta cheese. We're a Greek family and life is not worth living without feta cheese.
It will be very hard at first, but once you get into the swing of it you'll find your level. We don't go to the mall unless forced to. I rarely buy new clothes--actually, I can find a lot of good stuff at the thrift store. Why pay $60 for jeans when I can get them for less than $10? We do not accumulate "stuff." We don't take swanky vacations. We camp in our old paid-for camper. Both of our cars are old--we never buy new. We raised our insurance deductibles. We only give birthday or Christmas gifts to a select group of relatives.
It might sound like a bleak life, but really, once you start letting all that stuff go it frees you up for a different kind of life. We don't feel deprived at all. We learned to enjoy getting outside--sunsets are free. And campfires don't cost much either.

Together you'll get through this.