I currently have 3 mouth ulcers, they have caused a lot of pain in my throat and are stopping me doing simple things, what's the quickest cure?

Viral: If they are viral you can ask your pcp for Acyclovir tablets especially if you get them regularly and they will 'cure' them faster than mother nature; she takes 7-10 days. If you do not get them regularly the choice is yours. Mouth ulcers generally do not affect the throat so see your ent/dentist.

See your doctor: Mouth ulcers can be caused by a number of different things. The quickest cure will be dependent upon identifying the cause of the ulcers and treating it with the proper modality.