Wedding so without prying if you don't want to say so, were you in care as a child? You say you have no mum, dad, siblings, or extended family; you say they didn't exist. You obviously had a mum and a dad who are either deceased, or you are adopted perhaps.
Not all children have two parents in their lives; there will be zillions of women who come along here and say their child has no contact with their biological father or anyone else who is a relative by blood.
I think what me and others are trying to say is 'what do you want to do next?'
Your first post stated categorically that it was all too late, not going to happen, yet lots of posters have come along and said they had a child at 42 or whatever, with someone they met either by chance or by getting out there.
Do you want to do any of that?
Yes, it's understandable to not reach certain milestones (set by yourself or your biology) in life and feel sad but the question now is how can you change that?
It seems that whatever anyone suggests here today, you counter it with a negative. I can't see you have once said "oh yes, that's a good idea, I'll try it. " you don't seem to want to change anything.
If you really feel down and unable to see a way forward, you might want to see your GP or arrange your own support such as counselling, CBT or life coaching to help you move forward.
Your reluctance to even see that change is possible, is what's worrying as it seems to suggest you are depressed.
And the voluntary work you no longer enjoy- give it up! Don't waste another minute of your life doing things that give you no pleasure. use that time to spend on what you DO want.