I'm diagnosed with mixed personality disorder with avoidant, dependent and schizoid traits. So perhaps I know a little bit about where you are coming from.
I agree that being diagnosed with a personality disorder is alarming. There is not much information out there that is very optimistic about changing when you have a PD. And I am 53 years old! And still very dependent on my therapist. And I hate that.
I also have tried bucket loads of antidepressants and none worked. I was on 5 at one time, with Abilify added in to augment the AD. The Abilify numbed me out some, which was a relief at the time.
The good news is that I believe I have found a therapy style that helps. I am less dependent, less depressed than I was a year ago. And this is after 5 years of deep, dark depression. The technique is called brain spotting.
Other than that, I have read that long term therapy can help. DBT helped me get along for many years-maybe that is something to consider.