Off Work Due To Sickness..

I work for the NHS and due to my morning/all day sickness I've been off this past week (I only do 2 nights) I've been to the doctor and they prescribed me cyclizine but problem is I've to ring in every day to tell them how I feel. It feels awkward and I hate letting them down but I'm so unwell I couldn't face a night shift..thanks for any response.x