A quick update on my recovery (which is on page 37 for anyone that can be bothered to read the mammoth mass of text).
It's been around 2 months since the last time I rolled, and things are improving greatly.
I just got back from a 10 day holiday with my girlfriend, from London to Paris and then finishing up in Amsterdam. I think being away, and having lots of external stimulus for my mind to focus on, helped me to forget about my symptoms.
My HPPD is still present, although it's nowhere near as prevalent as it was before, and its only really noticeable when I look for it, when I've been drinking or when I smoked some joints in Amsterdam (Although I suspect this might just be the normal effects of grass, and I'm just noticing the vividness of colours more).
The brain fog has lifted a lot, and I'm actually able to properly construct sentences in my head, which, in turn, has removed a great deal of worry and the "OMGZ I'VE MASHED MY BRAINZZZ!11!!" thoughts.
I smoked 40mg of DMT before my holiday and ever since then my anxiety has disappeared. I'm a lot more chatty and feel more like my old self again. I obviously do NOT recommend that people try this as I think it could have just as easily have went the other way. I don't know exactly how DMT effects the brain, especially a recovering one. Maybe someone here that's more knowledgeable about neuro-chemistry could shed some light on why this is/isn't a good idea? All I know is that it worked for me.
Bowel problems are still present, although there is slight improvements here also. I only shit 4 times a day now haha

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I've still been doing psychedelics and drinking on a weekly basis during my recovery and am still using caffiene. I'm going on a 5 week inter-rail trip in 6 days time. Starting off in Amsterdam (for the 4th time this year :D) I'll smoke weed and take mushrooms while there, then I guess there will be a fair amount of alcohol consumed during the rest of the trip, and probably lots of caffiene too. I'm hoping my symptoms will have improved even more by then. After the trip I'm having a month+ break from all substances to let my body properly heal itself and finally kick my caffeine habit.
I wish everyone else all the best with their LTCs. I try not to read too much on here, because, as a hypochondriac, I don't want to pick up any more symptoms. I just wanted to give anyone out there struggling with this condition one more hopeful recovery story. Writing down each step of my progress also helps to cement it in my brain that I am actually getting better. See you guys in 6 weeks