I do not think that there is anything to stop you from contacting Social Services yourself.
They will (should) have a 'Care of the Elderly' Team who will (should) help you and your Mum.
Obviously, speak to her Dr too, but do not let getting through to him/her delay you from speaking to Social Services.
Have you tried looking at your Local Council's website ? If they have one it will probably list the services they provide and how to access them.
They should also have an 'out of hours' or emergency service so that , if, God forbid, Mum deteriorates before you can get things fixed up, you shoudl be able to make contact with someone who can help.
Good luck and all the best.