Help how often should i wash my hair?!?

I have a very dandruff prone scalp that when i don't wash it everyday, i get dandruff. And if i don't wash my hair everyday, it gets oily. and looks and feels gross. However, i guess its healthier to not wash your hair everyday? But me i'm a clean freak and i have to shower everyday usually if i go somewhere prior to the same day. I don't want to give up bathing everyday but i want my hair to be more healthy and not so dried out but it won't be oily. I have somewhat of bad fried ends too from straightening my hair almost all the time when school was in session, now that its summer i want my hair to rest. Any suggestions?!