Some really interesting comments on nutrition here that I think need to be addressed. To start with, my degree is in Nutrtion, not that im bigging myself up, Id just like to think that backs up what Im about to say. You will EASILY get all essential amino acids on a plant based diet, infact you don't even need to think about it at all. Baked beans on brown toast has a better ratio of essential aminos that beef steak. Unless you are living on lettuce its not even something to consider. As for protein, we have become increasingly obsessed with eating more of it, and this is actually having negetive effects on health, especially when from animal sources. Have a read of the china study. I myself have had mild hppd for the last 4 months and in the last month have reverted back to a plant based diet after 2 years of eating meat again (used to be vegan before), and the extreme depression has lifted, my anxiety is still there but better, my dp/dr is more managable, and most of all my visuals have calmed downed somewhat but unfortuantly still bothersome
im also continuing bodybuilding on a vegan diet! Check out bodybuilders like jon venus, brian turner. The worlds strongest man is vegan. If protein was an issue then building muscle on a vegan diet wouldnt be possible! The meat/food industry has done a really good job at promoting the importance of protein, so much so that we have become obsessed with protein. You know have food products in the UK that are being supplemented with extra protein. I saw soup with added protein in the other day! And these products arent marketed at bodybuilders, rather the general public. It baffles me! Not so long ago, smoking was considered healthy thanks to clever marketing. Sorry for my rant, I just get a little wound up when people are giving out nutritional advice without actually using any factual information. Im also not preaching a vegan diet either, people can eat what they want to eat, aint my business. That being said I think a plant based diet is essential for any illness including drug induced disorders such as HPPD, dp/dr, anxiety, depression etc for a number of reasons; eating higher quantities of nutrient dense foods, alkaline effect on body, removal of most dietary antibotics and hormones, known to improve mood disorders. I think the hormone/antibiotics one is so important especialy for HPPD, consumption of these things could be potentially agrevating and preventing/slowing down recovery. This is just my firm opinion of course, theres no studies to back this up.
As for fasting Ive not tried it myself, but maybe give intermittent fasting a look into and try that first. Sorry to hear youve had hppd for so long too.
Peace brother