I'm thinking you need MORE cortisone. Have you tried licorice tea in the morning to help with the nausea? Nausea in the am is a classic low cortisol symptom.
What happens when you take NAC (N-acetyl-cysteine)? If you can tolerate it will help both liver and kidneys. When I am having bad days and I take NAC, I begin to feel better in an hour or so. Granted, my AF is no where as bad as yours. Reduced Glutathione will help with methylation too. I know when you feel as bad as you do, just the thought of swallowing pills will make you want to hurl.
Are you taking salt in water or capsules (assuming you don't have problem with Aldosterone (I think that's the one that can cause problems with salt retention) or renin. I am not up to speed on either of these so I am not sure which one is involved with sodium retention, but I do know that it is mentioned quite frequently on the yahoo NTH Adrenal board by folks with really low cortisol.
Melatonin and Tryptophan raise serotonin levels. You might want to try those instead of zoloft. Consider elavil (amitriptyline) in low dose. It is also an ssri and has fewer side effects. I've been taking it since 1994 and have gone from 75mg to 25mg. I've been able wean myself off of it several times. The only withdrawal symptom I experienced was sleep difficulties for a few days until my body got used to not having it to sleep at night. Elavil is a very old SSRI (one of the first) and is typically prescribed to fibromyalgia patients for sleep, since they have a hard time sleeping at night. That is how I got my first rx for it. Elavil has gone generic now, so it is very, very cheap. Walmart sells amitriptyline for $4 for a 30 day supply.
5-HTP, makes me nauseous every time I take it, I think you mentioned that you found a site that said it lowers cortisol. If that's the case, then you definitely don't want to take it.