I don't really know. But having it intermittenly sounds better than having it permanently obviously. Would you mind sharing what happened during that session after which you felt better? What kind of things did you talk about during the session?
I think opening up about the condition to somebody, especially a professional, was the reason for why it went away. Its reassuring and makes the condition seem less frightening when you get it out there. It lowers anxiety and thereby relieving dp/dr. However, when it comes down to it, its also only a patch solution.
I firmly believe its possible to get rid of it 100% but that is only from my own experience of having had it for 1 year and then be cured for 3 years. During that year I had ups and downs but the condition was always there to a degree. I never felt I was 100% myself at any point before I was cured.
I'l tell you what my experience taught me. What got me out was lowering my anxiety overall, and to do that you have to find out what is causing you stress/anxiety. If the condition itself is the largest cause of your anxiety, you have to raise your confidence and trust the fact that the condition is not dangerous. It won't give you braindamage, it won't make you insane and it won't make you do anything you don't wanna do. Raise confidence in yourself by doing new things. Do the things you are afraid to do, like hanging out more with friends, meet new people, try a new hobby. Anything that will raise your self-confidence you should try and pursue.
My anxiety/stress came partly from the condition but I also realized I was lonely and my life was very uncertain at that time too. Once I socialized more and my life became more stable and I started doing things that gave me confidence, the condition fully disappeared and I was cured for 3 years straight without a single relapse. It only came back last month because I had let my life circumstances become bad again and my self-confidence dropped due to various things
Take my experience as you may but one thing I would def recommend is to never do drugs again! Our brains are simply not build for that kind of thing.