What exactly is it that you do? Are on a permanent contract or zero hours?
It seems with the shift work, no DP, no support other than paid babysitting, you would find this very difficult.
How much do you have left after bills now?
I think also when PP suggest qualifications, they don't necessarily mean a degree. Have a look at other job openings in your area. What are they? Which are stable office hours, how much are they paying? What experience do you have that could translate into one?
You say you're not good at maths, me neither, and I report/manage budgets on multi-millions of dollars on projects and have no qualifications. it is in fact, not rocket science!
However if i were in your position, I would be looking at a secretarial/pa course or even paralegal. Classes at night before baby gets here. A years training, get an office job with stable hours. Job in law firm, train as paralegal while working there. Many other options you can look in to.
1 bed flat not a problem for now and if you can improve your income, by the time you have a 5yo, you could be in a 2 bed.