PG you can be a good mom without much money, even if you had to do it as a single parent. If all you're focusing on is what you CAN'T give them, then you won't see what you CAN give them. I have 4 kids too, and we have lived below the poverty level since their father and I separated 12 years ago when my youngest was 4 and my oldest was not quite 14. Because he refused to pay child support at times, we were homeless twice, once for almost an entire year. But there was help and support from their schools, and our community, and as my kids grew they turned their disadvantages into strengths. Twelve years later, my oldest daughter is now a social worker who uses her own experiences to teach people how to be resourceful and how to advocate for themselves. My sons, both now young adults, often tell me that they had opportunities their more affluent friends never had. While I felt like a terrible mom because I couldn't afford all the camps and programs their friends attended, my sons now tell me they have the greatest memories of doing things with their friends like building forts and designing racetracks for their bikes in the woods, because they did those things on their own, using their imaginations and whatever resources they could find. Their more affluent friends often tell them they wish they could have had those opportunities instead of every activity being designed and supervised by adults. All 4 of them are hard-working, responsible kids who can hold down jobs without the sense of entitlement some of their friends grew up with because their friends got pretty much whatever they wanted.
I guess what I'm trying to say is, don't give up. Don't put so much emphasis on what MIGHT happen or even on what IS happening right now financially. You can give your kids much more than you think you can give them even though it may not be apparent to you right now. It wasn't apparent to me either until my kids grew up and told me that the most important thing was that I was there for them all along and I never gave up.