But you said there are medications that are improving it, right? AvPD doesn't work like that.
It's possible that you've had a condition for so long you don't remember life without it. That doesn't mean it can't improve.
I suspect you have fears of change and that you're grasping at straws to stay where you are. That's cool. But don't let it limit you. Tell your therapist what you've been thinking, that successful treatment is making you question your diagnosis. (Think about that one for a little bit.) Therapists are trained to help their clients through the feelings that come up when changes start happening.