I agree with the other posts. Affective instability has different causes. Your diagnoses can definitely influence the regulation of emotions. More information can be found here: Emotional Dysregulation - Psychological Treatment

I have ASD and struggle with this, but it is different from the BPD variety. Sensory overload makes me moody, rather than fears of abandonment and interpersonal sensitivity. In BPD, affect instability is intense and frequent and consistent over time, which is not the case for me.

The coping strategies seen in BPD such as self-harm, substance abuse, anger outbursts and eating disorders are related to affective instability.