Postgraduate Loan Options

Hey, I'm an Irish Civil Engineering Graduate planning on starting postgraduate studies. Initially, funding was not a problem as I have taken up Summer work to help with the fees and my parents offered to help out on what was left.
Circumstances changed and my parents have done a complete U-turn on their promise, letting the ~£20,000 living/fee costs rest entirely on my shoulders. I'm 22 years old and I just finished my final undergraduate exams less than 2 weeks ago, I will not be able to solely fund this by myself.
I've looking into options such as a student loan but it seems I'd only be entitled to £5,500, that, plus the £5,000 I obtain from work would barely cover half of the initial costs, irrespective of hidden fees associated with postgraduate life.
Are there any sort of larger loan options available for non-UK students (as I am an Irish citizen) or any other means of paying for my postgraduate degree? It's extremely difficult to find any sort of support for a person in my situation, I'm poor, yet my parents are not and they refuse to give any sort of financial assistance despite having given it to my other sibling just a few months ago.
I'm unsure what to do and would be very grateful for any sort of links to other funding opportunities that may be available for me.