First thing I’d do is cut the water supply under the sink - usually there’s a valve near the pipes - then give the area a quick wipe to spot where exactly it’s dripping from. If it’s coming from a joint or trap, a little plumber’s tape can temporarily hold things together. I’ve leaned on https://www.pm247.co.uk/services/plumbing/ before for drip disasters like this - they’ve got solid emergency support and don’t leave you hanging