this would all depends on ur CR too i bet u was using Singular, Singular is nice for a default one but with some classes u just need something better, i had this problem with a shadow priest until i changed to something different
When I was younger I always use to joke my priest had diabetes.I thought my mage just had a serious drinking problem...and his many deaths were a result of liver disease/obesity.
Seriously... fight, eat/drink......fight, eat/drink.......fight, eat/drink.....fight, die......
Such is the life of a mage....