Disassociation or Flashbacks?

[Neonpossum]

Hey everyone, I'm brand new here. I was initially diagnosed with BPD around 2005 and then, in my new psychiatrists words, it went 'under the radar' for a while as I was on high doses of all sorts of drugs. I've just been changed to venlafaxine and I have started having a lot of symptoms again, and it's upsetting. My emotions are extremely out of whack and my partner says I am often 'off in the clouds'. Most of my disassociative episodes are either bright colours, being unable to move my body, dellusions or just a numb feeling in which I stare into space. I also have memory loss, hearing reduction and such.

I also often have what my psychiatrist called flashbacks, though I have always associated them with PTSD (which I have never been diagnosed with). I have had traumatic experiences in my life, but never something so bad I feel it would cause PTSD, except maybe one. When I have flashbacks, I find myself in another year, at another age, with everything surrounding me from that time. They range from the bad events and environments, to remembering a new alarm clock I had. But I am there, I taste, feel, hear and see everything from that time. I don't understand what this is, could it be flashbacks? Or is it something else? 

I'm pretty confused, thanks for reading!