As a full time student you should be exempt from council tax but you must check with your local Council Tax benefits office to see if you need to fill in an exemption application,, an exemption certificate will then be issued. You may be able to claim Housing Benefit based on a low income which may give you an amount towards your rent, but you need to fill the form in from your local authority for that.
I think you should qualify for free dental and optical care anyway as a full time student.
You also should not pay any tax on your �4800, you should check with the tax office and make sure your employer has the correct code for you and filled in the right form for a full time student employee.
Depending on the University or College, there should be a Student Welfare fund that will offer you lump sum payments that did not used to be repayable, check with the Student Support office. (Or similar)
I do not think you qualify for any Working Tax Credit as you have to be 25 I understand. (Check that out though)
Someone else may have further ideas no doubt.