Please tell me can diabetes give you a slight headache or fever all the time?

Headaches, yes . Diabetes could be a factor in chronic headaches especially if your sugars are erratic, you have frequent hypoglycemia or your DM is poorly controlled. True fever with body temperature over 101 would be more indicative of infection. Diabetics are at higher risk for infection. Sweats without actual fever can be a symptom of diabetes .