You have done the right thing by informing the DVLA medical section , failure to tell them is a £1000 fine , their medical section is a law on to themselves , not sure how their own Doctors are chosen , loosing the HGV for your time period is not too bad and quite short , communication between your Doctor and the DVLA is very slow , they will not divulge information over the phone .
For financial help , maybe check the Government website for Universal Credit , they offer loans which come out of the benefits , contact the electricity and water company to ask for a reduced bill or later payment options , the same for council tax .
Worst case scenario is a food bank , i wish you luck . Be careful what you tell DVLA over the phone , as what you tell them is set in stone .