The structure you imagined contains oxygen with 4 bonds which i think is not possible and also all Oxygens are attached to Nitrogen and no Peroxy bonds : )
NO3- is Resonance Hybridized [PM me for Structure : ) ] .. and it accepts a H+ and it may be added to any O- randomly .. Then you get the stricture Like ..
OH
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O<--N=O 1. nitrogen is SP2 hybrdized,bonds in 120 with each other
2. SP2-P Sigma Coordinate Covalent Bond
3. SP2-P , one Sigma and one Pi
4. SP2-P , bond with O- which again bonded to h+
Browse for CO3-2 for similarity so that you can be more clear .. it accepts to 2H+ and forums H2CO3
Hope it Helped and i am correct : )