O sweetie. I just got out of a 5 year relationship with an ISTJ. We met in a video game about 6 years ago. I moved across states to be with him after 2 years. He would always ask me questions about every little thing - even down to who I talked to that day.
I kind of shrugged it off thinking he was just a very inquisitive person. Then it got worse.
I started getting spied on. I had chat logs restored from a formated hard drive - that out of months of logs etc he found one item that could even be considered questionable - and I heard about it for years even after proving my innocence. It got really bad.
The thing is in his mind me not divulging every single iota of information meant I was lying or hiding something. In our minds it really isnt a big deal - but to some S.O.'s its a HUGE DEAL.
There is no way to get him to stop. You need to just answer them the best you can. Offer the information if need be because the next step is the accusations and then the snooping. Hell, you may even take notes if you have to so that you can remember!!!!
I don't know if its a type thing or what but I could have written that post up there a few years ago.