Hi J.
A couple of minutes ago I felt like doing some self enquiry meditation before going to bed. I sat down and I felt my skin was paper thin, like my boundaries could easily dissolve. I felt tempted to just give in and just "surrender" and the subtle and weak flickering in my eyelids that has been there for about 3 weeks now started to become really intense and again I felt like I was being dissolved and I was struck by DEEP TERROR. My heart started pounding in my chest and I just decided to open my eyes. I was calm a couple of minutes afterwards.
I have no access to a good teacher currently and I'm afraid I might be debilitated by whatever darkness that may arise.
What do you think is going on? Is there a way to stop the progression and wait until I have access to a good teacher or continue on retreat?
Maybe keep in mind that the build up to this experience was positive for you. You mention getting calm and peaceful in the weeks before hand. This sort of thing has happened to me only a handful of times to me 25 years. When the dissolving starts to happen, if there is also a lot of mental calm or you have the nature to be basically open-minded or not knowing/not assuming, then a variety of perceptions can occur, like out-of-body perceptions.
When these have happened to me during "practice" they are out of the blue, but they occur with that obvious preceding comfort in the body and the spreading of boundarylessness and the mind is willing to let that feeling become suffusive because it is very comfortable. At some point, yes, perception can get very unusual: one can perceive deep, fast sinking or even rising into space really quickly, soaring or just under stillness in an empty, limitedless field. At some point during these perceptions "I" do come back and naturally I have a jolt of kind of "What the whoha is going on?" There have been occasions of even feeling paralyzed, not breathing-- and now I just know the brainstem releases adrenoline and makes sure the party gets started. Usually there's a deep gulp of air that I don't trigger.
So I wouldn't worry about it. The preception-event may happen, that event may change your conduct (it has always caused me to adjust some way I think strongly for the better) and when "you" return during that event it's very normal to be returning during the body's natural adrenoline, suddenly or in a slight panic. I think dying in meditation is very rare, but it's not a bad way to go if that's what happens.
So these events can be fun, nutty, mind opening and also a distraction: they are just part of seeing things as they are. This sort of atypical-to-our-normal life perception event is just one of the ways mind can be aside from being a social mind, a bill paying mind, a family mind, a friend mind, a grumpy mind, a sad mind.
In my opinion, it's okay to surrender to these perception events happening. Your body and your ego will reel you back in until you feel very safe totally surrendering. You can just set your intention at the outset, like "May I be able to relax and experience whatever is coming and trust it will be okay and help me be less harmful/manipulative in the world," for example, or "May I not have these events happen and just watch the mind arise and pass without this sort of deep sinking and expansion"...