OP "yet I'm being told off like a naughty child for not wanting to help myself?"
I don't think you are being told off. You came on here and asked for an opinion. You've drip fed - which always makes people irritable - but even now I know that you own a home outright, you say it is in a cheap area in the north and you can't move to a cheaper place and get a 2 bed.
so you are back to having an income that isn't low - given no housing costs - but is unpredictable.
therefore you will need regular reliable childcare for unpredictable hours.
You feel you can't improve your earning power, fair enough.
you say you have no support network.
so ultimately - yes, YABU to have a child. And as for "having a baby" - I don't interpret that the way some posters have done i.e. can I afford the baby stage and try to up my income later. I hear it as "can I afford to raise a child till at least 18".
The world is a very different place than it was for our parents. You won't necessarily find a way to earn more. Housing may continue to be stupidly expensive. Your child will need a room for themselves and you will need childcare etc etc
that's just looking at the very basics.
so even post-dripfeed - no, you can't afford to have a child.
Unless you are about to tell us of some secret trust fund you come into at 40....!