Hello every one!
I'm a recovery addict of codein (not daily), and I used a lot of dissociatives psychedelics, and others stufs like GHB and empathogenic uppers etc... I've done 3 vipassana retreats of 10 days Goenka style + one I left before the end.
First tentative, left on fay four, was consuming vast amount of GHB just before the retreat, stupid I know^^ (3 years ago)
First one, 2 years ago was great! No problems, extremely difficult but I left really happy!
Second one last summer, not so great! On the fourth day when starting vipassana meditation, all was good : Strong concentration, my bodily sensations dissolved until I have no body anymore for a few moment (as when I take a dissociative) just at the last meditation of the day. Then the morning after, suddenly a freaking sensation arose in the area of my heart. Like a hit of a knife on my chest! The sensation was an unbearable emptiness in the area. I cannot focus my awareness directly on the area (I tried but felt a starting panic attack so I stopped^^). I tried to have support and explications from the professor, but he was a little bit evasive (like "stay equanimous babe, all is anicca who know?" haha^^) When I stopped the meditations sitting, the sensations was still burning with force like it was dissolving. At a moment, my equanimity vanished for a moment when I thought "it this shit will stop?" So the sensation stopped burning, but instead I had severe anxiety. So I forced to calm myself and my equanimity return, with the burning sensation (not so unpleasant but with a continuity and an intensity a little bit freaking^^) Am my still clear? I hope so

It was day five out of 10, and didn't sleep all night, because I had to stay equanimous about my sensation. I tried to stay equanimous, and dissolve the heavy sensations that was constantly liberated by my "heart-emptiness sensation". Stopped vipassana meditation at day 8 to 10, and limited myself to anapana meditation (concentration on breath instead of body scan) from. Okay, retreat over, still living but I left the course a little bit shaking!
A year pass, with increasing drug use. I started to visit a sophrologue, and an EMDR practicien a 2 months ago. I think that EMDR therapy vastly decrease my craving for drug use. So I went again in an other retreat that just stopped this morning. I had no hard drug use for a month before this retreat (epic for me). The retreat went great, difficult as always but great. But, hehe, I still have the emptiness-heart sensation (Annica my ASS

) I worked again on it and it was far less intense! At the end of the retreat (so yesterday and the day before yesterday), painfull emptiness was remplaced by a feeling of healing. Like when I passed my attention on my body, piece by piece, little ropes on all my area of the chest was adjusted. Like some knots was undown one by one. This time, I left the retreat so rejuvenated!
But but but^^ I've just sitting one hour a few minutes ago, and the intensity of the heart-emptyness came back, not in force, but still a little bit disruptive. I fix my attention on my palm right now and the little anxiety decrease and I feel the "healing sensation" a little bit in permanence even if I'm not in sitting position.
I really hope I wasn't too boring writting this! If your still here, and if you have any thought about what I'm experiencing now, please leave a comment!

Any input will be appreciated! I feel in control and happy of the healing sensation, but I try to interrogate some others vipassana meditators and they didn't seem to be confronted to the same thing that me. Is it because I had drug consumption? I had 2 major badtrips a few years ago on a mix of drugs. I was afraid that vipassana could have create more arm than good to me. But this time I want to sit 2 hours a day, and leave my addiction and start meditating seriously. I'm exhausted from the feeling of craving drug. I want the peace and delightful relaxation that is created sometime after my meditation.
May all of you be happy