OP, I read this thread earlier and felt quite sorry for you because I don't think most people are hearing your situation.
It's very very different to decide to be single, as I am currently, when you have had several relationships, marriage and kids. Of course after 20 years odd of childrearing, you are done in and starting again less tempting.
That's not your situation though, I don't think, I get the impression you are not in a relationship, don't have children, and that is fading away as a life choice for you (I don't know about this last bit).
I have lots of childfree friends, but they are all in long-term relationships (they are 40's and 50's now). I have a couple of single friends, through being widowed or divorced, all have had children. Being single in this situation is indeed pretty desirable.
I think those saying love and marriage don't matter, or are just social conventions, are missing the point- you feel lonely and you say you don't have a loving family either. That is indeed a loss and something I think I'd talk through with a counsellor/therapist- to find out how you can move forward, attract more people in (whether friends, relationships) and so on.
Saying I've had three relationships, two kids and I'm single isn't helpful when that's not the situation of the OP!