hi ang1021, i have had long experiences of the disorder too, but it ok at moment.
I worked out its a defence mechanism i created when small child to overcome intense fear.
not seen walking dead, but heard of it, im guessing something in the program made you feel scared and it triggered this episode.
im doing a BA degree and have a mental health support worker through the university. it helps a lot, they remind me how well im doing by just turning up! and stop me being so hard on myself.
I know from experience it can just be a time thing, time heals my dissociation. i don't take anything anymore, no anti anxiety because it made the detachment worse for me. the doctors medication you on may be helping you but maybe its proplonging your episodes too, its complicated stuff, maybe try talking about it to your health workers.
The meaning of life is helping others, we are not important ourselves , the only useful thing about this life is making it a bit better for others, even if its just a smile you give a passing neighbour , or being kind to that grumpy shop assistant,
im not a christian but i live by the words of jesus, he said life is about caring for others not ourselves and he's right.
if it was about ourselves, i would of left years ago.

i don't take meds for the same reason that they tend to make my DP episodes worse not better, as well as you become dependent on those meds(when they work) to make you feel normal and if your dependent on them to feel normal you can't stop taking them. i find simple exercise as breathing techniques and telling myself as many times as it takes that everything is okay, and there is nothing to be afraid of, and i am safe and there is nothing to worry about and other variations of that. when you repeat things to yourself over and over it tends to sink in to your subconscious mind letting you relax, now it can take sometime for that to work and it helps if you constantly do it. i have a lot of trouble relaxing and falling asleep and find that do those exercises helps me relax enough to fall asleep, normally it could take me hrs for that to happen but since i started doing these exercises i have been able to fall asleep so much faster and it works for more than just sleep, but you need to stick with it and not get frustrated if it doesn't happen right away. as for questioning the meaning of life i do the same and if i let it it can freak me out cause when you think of life, it's kinda crazy that anything exists at all how the universe came to be how everything is dependent on a certain balance, you just have to tell yourself repeatedly that you may never understand and you have thought enough on the matter and don't have the answers and may never have the answers and it is time to put the matter away till you come up with something that you feel explains it, otherwise it is a pointless waste of time to be fretting over something you can't puzzle out. remember to relax and stop yourself from stressing over things that in the grand scheme of things is not so important. hope so of this helps!