Is there a reason you can’t move with your Mum, at least near to her? You’re going to need help and support from time to time. If the council aren’t helping (which they have a legal obligation to do, though I don’t know the full conversations you’ve had) then try Citizens Advice first thing in the morning. Also, try here:
Support with any parenting problem: Family Lives 9am-9pm weekdays, 10am-3pm weekends FREE helpline 0808 800 2222 http://familylives.org.uk
You could do that right now!