Hi Clare.
No doubt someone will post a better reply however I too had this experience. Following radiotherapy and some chemo for squamous cell carcinoma of my tonsils I lost all sense of taste. It really freaked me out.. aside from all the other stuff. The Consultant oncology radiotherapist did not appear in the slightest phased by my concerns regarding this. It is really scary to have this happen!

It is fair to say it took a good 6 months to get my sense of taste back. Over a year maybe to fully recover. For a while it was very odd with exaggerated tastes of some things. Spicy food was intolerable. However all this passed and, in my experience, all returned to normal.. including my saliva output. 
Best to chat to your oncologist but can at least demonstrate how temporary my own experience was. Wish you well. 

Paul. x