The simplest solution would be to simply apply the necropolitan template (Libris Mortis). Your character's creature type would change to undead (dragonblooded, reptilian). You'd have a Con score of - and you'd gain undead traits. Nothing else about the character would change - no HD, no LA, no other modifications, no muss, no fuss.
If you have the Dragonwrought Kobold feat, that might introduce some type weirdness with the template, but you might refer to the "type pyramid" from Savage Species to help resolve that issue. That would result in the dragon type being overruled by your transformation into an undead. Consult with your DM on what will work best for your game.
