Unfortunately, off and on for the past 11 years, but that "off and on" caveat is important. Of all that time and effort, much of it was either half-assed or out of order. It is my opinion that cognitive therapy is doomed to fail or may even be counterproductive in people whose psychology is too shame-based. I had to be convinced that I wasn't inherently defective and was capable of positive (if incremental) change before I could really get anything out of most therapeutic approaches. This required hearing the message from fellow sufferers who not only got better but had the balls to be candid about their life stories. For many, Brene Brown fits this bill. I needed John Bradshaw. Though I did not use his inner child self-help techniques, his vivid and thorough explanation for the destructive force of shame was sufficient to convince me. I then reinforced this new understanding by attending a very informal group therapy.
Medication has so far been small potatoes for me. The only lasting, tangible benefit I have received has been from meds which help me sleep - e.g. trazadone, quetiapine. Quetiapine in particular has helped in the past to diffuse anxious rumination spirals. Valium prevents them handily in the first place, but good luck getting an Rx for any appreciable length of time due to the abuse/dependence potential.