Do I live in DC or MD? Sort of lived in both last year, have a lease in DC now, but still get all my mail/license/voters registration attached to my parents' house in MD.

Not really sure what state I "live" in. Was born & raised in Maryland, attended college in Washington, DC (was still technically a permanent resident of MD). Got a full time job in Virginia in the summer of 2016 while I was still living in MD (my "permanent residence" I guess was my parent's house in Baltimore County and I was actually subletting/living with friends in Montgomery County). 

In the summer of 2017 I got an apartment in DC, (was on the DC lease for under 183 days,) still get all my mail and stuff all my accounts are registered to my parent's house in Baltimore, I still have my MD license, am registered to vote in MD, drive a car that's registered in MD (either to my parents or myself...), am on my parent's health insurance, car insurance, cell phone plan, etc., and I still work in Virginia. I'm on a lease in DC and it's like, where I sleep at night but a lot of things on the internet says like, you live here if you live here now and don't plan on returning to the other state... 

I don't know for sure where I'll live next, though. DC and MD are so close I could easily move back and forth every year... but it would be ridiculous to change my residency annually. I don't personally own property in either jurisdiction but am considering buying in the future, and have been exploring both DC & MD. Any advice?