Throat cancer

Hi all my partner has had radiotherapy , he finished his treatment April 10th , he is really suffering with bad pain coming from his ear up to his head , it happens every time he eats , first thing in the morning, has anyone else suffered this , he has lost 4half stone , he can only get one little finger in his mouth , it just won’t open , he has been checked by the dentist and his teeth are all ok , as you can imagine we are worried, but trying to stay positive, he has his scan next week , thank you