Does your aspie fly into rages? Intensely fear abandonment? Have extremely poor emotion regulation?
If so, consider researching Borderline Personality Disorder. The website "Out of the Fog" has tremendous resources to help understand BPD as well as helps for understanding Narcissistic Personality Disorder.
It seems autism can have several different comorbid disorders. So, don't blame every difficulty on autism! Research personality disorders.
And if your loved one fits the bill for a personality disorder, definitely study Codependency. You may be caught up in a common disorder yourself, and without realizing it, you might be enabling the dysfunction.