I work in Delaware, I only have a w2 for the state of delaware but i lived in md, do i still need to file a tax return?

Unfortunately, yes, you need to file in both states.  You file in MD because you are a resident and all income earned while you are a resident, irrespective of where in the world it came from, is taxable by MD.  You file in DE because you earned income from DE sources.  Fortunately, MD allows a credit against its tax bill for income taxes paid to DE.

The Maryland site (http://taxes.marylandtaxes.com/Individual_Taxes/Individual_Tax_Types/Income_Tax/Filing_Information/D...) states:

Maryland residents who work in Delaware must file tax returns with both states. To avoid dual taxation, you can get a credit for taxes paid to Delaware and/or a locality in Delaware by completing Maryland Form 502CR and filing it with your Maryland income tax return. Be sure to include a copy of your Delaware return and/or return of the locality in Delaware.