HELP! Part-time postgrad loan impacting on my council tax and housing benefit

Hi guys,
I've checked out other threads on here but haven't found anyone in my exact situation and could really do with some specific advice right now.

I work part-time in retail, just 14 hours a week (weekends) and earn £450 per month.
Just before I started my post grad course (sept 17) I moved out. During the time before me being a student, I was making a contribution to my rent of £30p/w (i received £44 p/w housing benefit) I was also paying approximate £30p/m council tax.

I receive funding from student finance of £10,280. Obviously I am a part time student so this is split into £5,140 per year. The cost of my tuition fee is £9,900.

Since becoming a student, I have had so many issues with my housing benefit and council tax that at the moment I feel like I'm being forced to choose between being made homeless or having to withdraw from a course I'm weeks away from sitting exams for.

I have already disputed the decision made by the relevant departments. They have again decided that I must use 30% of my loan to pay additional rent and council tax. At the moment, they have decided that from my student loan I have an additional income of £36.71 per week and should be paying this additional amount towards my rent. In total they are saying i should be paying £55.20 a week towards my rent but due to them making "overpayments" since september, I am being expected to pay £68.80 per week until this is covered.

As well as this, they are expecting me to pay £255 council tax in february to cover the "overpayment" for this.

Clearly, this is going to prove impossible for me on a wage of £450. Ive sent off a copy of my my student finance loan breakdown, an invoice for £5000 for my tuition fees this year, confirmation of my student status to the uni including hours I am in per week and they are already aware of my work hours and income. I've sent 2 letters to them explaining this.

I'm living in a one bedroom flat which is over an hour away from my work and uni so I'm having to pay £5.20 per day to get there. Because of all of this, I'm going to work for 9 hours with no lunch whatsoever and if I'm hit with the above bills next month I wont even be able to afford to get to uni or work.

I've read about the rules relating to post-grad students in other threads but can anyone advise me at to what I should do. I sent off another letter disputing it today but I'm feeling far from hopeful right now. I was homeless for a whole year during my 3rd year of undergrad and was literally sleeping in starbucks, I have no family I can turn to and am really just trying to focus on my exams and don't want to have to go through that again. Any advise anyone can offer would be great.

Thankyou