The brain fog, confusion, memory loss is due to toxins not being eliminated. Are you using anything to absorb the toxins when you are doing parasite cleansing? I would immediately get some Sonne's No. 7 liquid Bentonite clay. Mix it with water and some fiber and drink it at least twice per day away from meals or supplements by at least an hour or two. Or you could try the Renew Life product, I think it is called Absorb More Toxins, it's a combo of Bentonite and Charcoal in pill, but I think the liquid is more effective.
I also take the NOW brand of Arginine/Citrulline supplement (I buy it at iherb.com) to help you eliminate the toxic ammonia that gets created when killing parasites. If your liver can't handle these toxins they will affect your brain fog, etc. When doing cleansing I take one capsule about 3-4 times a day on an empty stomach. I actually take it about a half hour after I take my Zymex II and Wormwood combination. If you have really big worms like Tapeworms or roundworms, the toxins that get created are enormous. This toxic ammonia just keeps recirculating in your body giving you those terrible feelings. Drink lots of water to help the Arginine expel the ammonia safely through your kidneys. I also take N-Acetyl-Cysteine to help my liver handle the toxins. I take several of these per day. The confusion and fog will coincide with the toxicity of your body but you can eliminate it with these measures. Listen to your body and slow down if the toxins are not getting eliminated quickly enough. Lecithin granules are also very helpful for your liver and for restoring quick, sharp thinking during all this cleansing. I use it several times per day, but especially in my protein shakes. I hope this helps.