Hi Tim,
You seem to be different in this respect then the most of the dieters here. Some even gain weigth though I myself can't imagine how they do that. I tend to answer to your question that you might ask to much of yourself and from the diet. There are probably people here who might think otherwise but in the light of your recent history the LSD and a little inflammation (and medication) as a result of it might be a better idea then going too strict and ending up without energy and in troubles. Even better is some alternation I think. The apple diet is very good as a sort of reset for your metabolism and intestines. And between those periods you could allow yourself some cooked rice or oats to resolve the energy problems (so you can keep moving and exercising) and to gain your weight back.
When I look at myself I also do it that way although I always seem to have some level of background inflammation even after three days of apple diet. The diet is working however but I keep needing some NSAID's though greatly reduced. Maybe others have other tips.

Coming back on my previous post for Wally I'd like to add that though I believe that most people who say diet doesn't work for them haven't seriously tried this doesn't mean that there could not be some kind of division in AS'ers and their response to diet.
Gerard

"That we become twice as old now as a century ago is the work of plumbers, not doctors" -Midas Dekkers-