Another single mama here who had no support for the longest time too.
I cut off contact with my mother 20 years ago, and only had minimal phone contact with my brother when DS was born. My father and stepmother are toxic, and I had extremely minimal contact with them up until last June when I cut them out completely. No financial support from them, mostly just them telling me what a crappy mother I was and how I was hurting DS.
No contact with DS's father, and no child support. I had no friends with kids when I had DS, and my childless friends dropped away pretty quickly once they realized I had to attend to DS instead of dropping everything to go shopping or out somewhere all the time.
It is hard. It sucks a lot of the time. You hate your life, you end up feeling resentful toward so many people. You cry, you do whatever it is that comforts you, and then you cry some more. Then you get up each morning, snuggle your little person and go out and ask for help. I joined a Unitarian church, called the Visiting Nurse Association, called a child abuse prevention hotline, a single mother's residence program, and many more. I asked them all the same thing. "What can you offer me in the way of help? I am a single mother with no community resources, no family, and no child support or contact with my child's father and am feeling like I am drowning. Please help." They all offered either help, or gave me names and numbers that I could call.
It does get easier, and when you are in the middle of the hardest, darkest days, it seems like life will never get easier, but it does. You make friends, you find other single mamas, and you hang onto them for dear life.
Just an example: Tonight I had a potluck at my house for DS's and my birthdays (we have the same b-day) and I had two single mama friends and their DS's and another mama and her partner and her DD who was a single mama when I met her. Three of the most supportive, stong women I have ever met in my entire life and their kids. I felt so rich, and surrounded by love. I felt like I had the strongest community and a huge family tonight. It honestly feels like some sort of magic when it all comes together. It can happen, but you have to ask for help.
Hang in there mama. You can do it, and your little ones will someday see how very strong you were and are and you will find your tribe.