For myself, my AvPD has traits unique to my other disorders. Procrastination, which makes CBT near useless (for me). Exposure, no matter how steady, makes things worse not better so its harder to go back. The 'avoidance' seems weaved throughout my whole life, Every aspect of it. All related to fear of course. Councelling helps 'unload'. Psychotherapy may well 'unblock' what keeps it going. Example, I was abused when young and allways felt dirty and odd- talking through it gave me a different viewpoint on it and now I never think of it. That never directly helped my AvPD but its one less burden. I would imagine also that most AvPD sufferers are or end up depressed whether its associated or not- Its hard being lonely. I would also imagine there is a high rate of addiction amongst AvPD sufferers too, but thats more an 'educated' guess. Addiction fills the emptyness that we feel from being alone so much. DEFINITELY join a local Social Anxiety self-help group if ur lucky to have one near you. Whether you can keep up with the meetings is down to you. I cant. Not at the mo.
AND MEDICATION 'DOES' WORK- VERY WELL! You'll need a specialist though who's willing not to give up as you wont get what you need from a GP (unless ur a lucky sod who responds to an SSRI ). Nardil (phenelzine) is a drug that brung me back to life- for a while. I now take clonazepam, isocarboxazid with trimipramine just added. Things were 'sort of' manageable 'till a feww months back when depression hit me from nowhere. Back in Nov'09 I asked a girl out and we had a 5 month relationship. Thats right, 'I' did the asking lol.
What keeps me going in my lowest moments is remembering what I HAVE done. All by myself. I should be proud of myself but the conflict inside negates all that.
Hope I've said something worthwhile.
Good luck!