Right Engine,
You appear to have the early signs of being affected as many other people before you have found out. It might appear to only last 12 hours but I think most sufferers would agree that it very slowly creeps up on you and soon lasts longer.
I have found that if you were to have a bad exposure or event one day, your body will take a big hit and your recovery will last a lot longer than a day.
I have found in other pilots that once they have had a bad exposure, their natural defences seem to weaken rapidly and even a small exposure in the future will affect them very badly.
I met a guy the other day who could barely talk and was in no way fit enough to fly; he had his exposure in 2004 and just battled on getting sicker and sicker. Poor fellow. No more flying for him. Join the club.
The worst part is that you know you may be on the way to being permanently brain damaged one day. Bit of a trap really.
I really think that people have to be honest with themselves here, if you think you are losing it, you are, it's not your imagination - do something to stop it, before it's too late.
There is help and advice available out there, now.
DB