Agree with PP, adoption isn’t realistically an option a lot of the time. It’s hard to be approved, is a very long process, and can be extremely difficult to cope with which is why the support network element is there. We have a couple of adopted children at school. They absolutely need and rely on their family support, because the children have lots of unidentifiable additional needs. They don’t just turn up as a fresh new kid, they will have brought their previous lives with them, and helping them through that takes some extremely hard work.
Re being single/no family with a child, though, I have a friend like this. She was with the dad, but he spiralled into a total prick during pregnancy and left when the child was tiny. Her own parents are addicts, the child’s father had some family but they don’t bother and neither does he. The child isn’t off with his dad EOW and the dad doesn’t contribute financially. My friend is very very happy. Probably one of my most content friends, because she knows that nobody is coming to rescue the situation she isn’t waiting around for any of them to step in. She gets on and does everything herself and is able to take real pride in her abilities as a mum and in her work. They’re great, she takes him all over the place travelling, he goes to extra-curricular clubs and friend’s parties, has play dates and all the rest. He’s not lonely because of lack of biological family. Between them, they’re having a fulfilling and loving life. She’s got friends, but has also made lots of new friends as you do when you have a kid.
I can see OP, that you’re craving a family as much as a baby. I think you may have to let the desire for a family go if you’re going to have a baby. It doesn’t always work that way even if it seems you’ll get a family at the beginning. My DH and I are almost totally alone in our parenting, my family are not really into the kids, and my husband’s massive family are even less so. It wasn’t how I envisaged being married with kids, I thought we’d have what others have, grandparents taking them out, aunties and uncles coming for birthdays etc etc. but none of them bother.
Look at all the threads on here about feuds with BIL’s, MIL’s, mums, dads, brothers and sisters. Having a ‘proper’ family isn’t always what people expect or hope for either.