Hey R.F.
I've had one or two of those conversations as well.
Obviously they want to make sure that you are ok. They don't really want to hear that you're not ok; but they just have to ask.
They will get around of course, to asking you if you are having any spiritual problems. In their opinion you have either committed a serious sin and are dealing with a guilty conscience or you're becoming weak in the faith and need encouragement before it's too late.
Let them know for sure that you're not having any spiritual problems but you are [insert your public fading response here] and are doing the best you can.
If you want to fade you can't give them any reason to suspect apostasy or spiritual sickness that can lead to apostasy or pulling away from the organization.
When do you think you'll request to stop being a MS? Perhaps you should play the depressed;sick;whatever card when you talk with them and use that as your excuse to step aside. Tell them you need time to get over your emotional issues.
Good luck.